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TABLE OF CONTENTS
Item 8. Financial Statements and Supplementary Data



UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE


SECURITIES EXCHANGE ACT OF 1934

For the Fiscal Year Ended December 31, 2005

2006

Commission file number 1-5153

Marathon Oil Corporation

(Exact name of registrant as specified in its charter)

Delaware
(State of Incorporation)
   
Delaware25-0996816
(State of Incorporation)
(I.R.S. Employer Identification No.)

5555 San Felipe Road, Houston, TX 77056-2723

(Address of principal executive offices)

Tel. No. (713) 629-6600

Securities registered pursuant to Section 12 (b) of the Act:*

Title of Each Class
Common Stock, par value $1.00



Title of Each Class

Common Stock, par value $1.00


Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. YesþNoo

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. YesoNoþ

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15 (d) of the Securities Exchange Act of 1934 during the preceding 12 months and (2) has been subject to such filing requirements for the past 90 days. YesþNoo

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’sregistrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.10-K. þo

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of “accelerated"accelerated filer and large accelerated filer”filer" in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filerþ Accelerated filero Non-accelerated filero

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). YesoNoþ

The aggregate market value of Common Stock held by non-affiliates as of June 30, 2005: $19.52006: $29.924 billion. This amount is based on the closing price of the registrant’sregistrant's Common Stock on the New York Stock Exchange composite tape on that date. Shares of Common Stock held by executive officers and directors of the registrant are not included in the computation. However, the registrant has made no determination that such individuals are “affiliates”"affiliates" within the meaning of Rule 405 of the Securities Act of 1933.

There were 366,808,670345,862,952 shares of Marathon Oil Corporation Common Stock outstanding as of January 31, 2006.

2007.

Documents Incorporated By Reference:

Portions of the registrant’sregistrant's proxy statement relating to its 20062007 annual meeting of stockholders, to be filed with the Securities and Exchange Commission pursuant to Regulation 14A under the Securities Exchange Act of 1934, are incorporated by reference to the extent set forth in Part III, Items 10-14 of this report.

  * The Common Stock is listed on the New York Stock Exchange, the Chicago Stock Exchange and the Pacific Stock Exchange.


*
The Common Stock is listed on the New York Stock Exchange and the Chicago Stock Exchange.






MARATHON OIL CORPORATION

        Unless the context otherwise indicates, references in this Annual Report on Form 10-K to “Marathon,” “we,” “our,”"Marathon," "we," "our," or “us”"us" are references to Marathon Oil Corporation, including its wholly-owned and majority-owned subsidiaries, and its ownership interests in equity method investees (corporate entities, partnerships, limited liability companies and other ventures over which Marathon exerts significant influence by virtue of its ownership interest, typically between 20 and 50 percent). Effective September 1, 2005, subsequent to the acquisition discussed in Note 56 to the consolidated financial statements, Marathon Ashland Petroleum LLC changed its name to Marathon Petroleum Company LLC. References to Marathon Petroleum Company LLC (“MPC”("MPC") are references to the entity formerly known as Marathon Ashland Petroleum LLC.


TABLE OF CONTENTS

PART I  
PART IItem 1.Business
 Business1A. 2Risk Factors
 Risk Factors1B. 22Unresolved Staff Comments
 Unresolved Staff Comments2. 27Properties
 Properties3. 27Legal Proceedings
 Legal Proceedings4. 27
Submission of Matters to a Vote of Security Holders30

PART II


 
 

Market for Registrant’sRegistrant's Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities
30
 Selected Financial Data 31Selected Financial Data
  Management’sManagement's Discussion and Analysis of Financial Condition and Results of Operations31
  Quantitative and Qualitative Disclosures about Market Risk53
  Financial Statements and Supplementary DataF-1
  Changes in and Disagreements with Accountants on Accounting and Financial Disclosure58
 Controls and Procedures 58Controls and Procedures
 Other Information 58Other Information

PART III


 
 

Directors, and Executive Officers of the Registrant
58and Corporate Governance
 Executive Compensation 59Executive Compensation
  Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters59
  Certain Relationships and Related Transactions,60 and Director Independence
  Principal Accounting Fees and Services60

PART IV


 
 

Exhibits, and Financial Statement Schedules
61
Schedule II – Valuation and Qualifying Accounts
SIGNATURES
66
SIGNATURES67
GLOSSARY OF CERTAIN DEFINED TERMS68
Form of Non-Qualified Stock Option Grant for MAP officers
Form of Non-Qualified Stock Option Award Agreement
Form of Performance Share Award Agreement
Form of Cash Retention Award Agreement
Marathon Oil Company Excess Benefit Plan
Marathon Oil Company Deferred Compensation Plan
Marathon Petroleum Company LLC Excess Benefit Plan
Marathon Petroleum Company LLC Deferred Compensation Plan
Speedway SuperAmerica LLC Excess Benefit Plan
Speedway SuperAmerica LLC Excess Benefit Plan Amendment
Pilot JV Amendment to Deferred Compensation Plans and Excess Benefits Plans
EMRO Marketing Company Deferred Compensation Plan
Computation of Ratio of Earnings to Combined Fixed Charges and Preferred Stock Dividends
Computation of Ratio of Earnings to Fixed Charges
List of Significant Subsidiaries
Consent of Independent Registered Public Accounting Firm
Certification of President and CEO pursuant to Rule 13a-14a/15d-14a
Certification of SVP and CFO pursuant to Rule 13a-14a/15d-14a
Certification of President and CEO pursuant to Section 1350
Certification of SVP and CFO pursuant to Section 1350



Disclosures Regarding Forward-Looking Statements

        This Annual Report on Form 10-K, particularly Item 1. Business, Item 1A. Risk Factors, Item 3. Legal Proceedings, Item 7. Management’sManagement's Discussion and Analysis of Financial Condition and Results of Operations and Item 7A. Quantitative and Qualitative Disclosures about Market Risk, includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. These statements typically contain words such as “anticipate,” “believe,” “estimate,” “expect,” “forecast,” “plan,” “predict” “target,” “project,” “could,” “may,” “should,” “would”"anticipate," "believe," "estimate," "expect," "forecast," "plan," "predict" "target," "project," "could," "may," "should," "would" or similar words, indicating that future outcomes are uncertain. In accordance with “safe harbor”"safe harbor" provisions of the Private Securities Litigation Reform Act of 1995, these statements are accompanied by cautionary language identifying important factors, though not necessarily all such factors, that could cause future outcomes to differ materially from those set forth in the forward-looking statements.

        Forward-looking statements in this Report may include, but are not limited to, levels of revenues, gross margins, income from operations, net income or earnings per share; levels of capital, exploration, environmental or maintenance expenditures; the success or timing of completion of ongoing or anticipated capital, exploration or maintenance projects; volumes of production, sales, throughput or shipments of liquid hydrocarbons, natural gas and refined products; levels of worldwide prices of liquid hydrocarbons, natural gas and refined products; levels of reserves, proved or otherwise, of liquid hydrocarbons and natural gas; the acquisition or divestiture of assets; the effect of restructuring or reorganization of business components; the potential effect of judicial proceedings on our business and financial condition; and the anticipated effects of actions of third parties such as competitors, or federal, foreign, state or local regulatory authorities.


PART I

Item 1. Business

General

        Marathon Oil Corporation was originally organized in 2001 as USX HoldCo, Inc., a wholly-owned subsidiary of the former USX Corporation. As a result of a reorganization completed in July 2001, USX HoldCo, Inc. (1) became the parent entity of the consolidated enterprise (the former USX Corporation was merged into a subsidiary of USX HoldCo, Inc.) and (2) changed its name to USX Corporation. In connection with the transaction described in the next paragraph (the “Separation”"Separation"), USX Corporation changed its name to Marathon Oil Corporation.

        Before December 31, 2001, Marathon had two outstanding classes of common stock: USX-Marathon Group common stock, which was intended to reflect the performance of our energy business, and USX-U.S. Steel Group common stock (“("Steel Stock”Stock"), which was intended to reflect the performance of our steel business. On December 31, 2001, we disposed of our steel business through a tax-free distribution of the common stock of our wholly-owned subsidiary United States Steel Corporation (“("United States Steel”Steel") to holders of Steel Stock in exchange for all outstanding shares of Steel Stock on a one-for-one basis.

        In connection with the Separation, our certificate of incorporation was amended on December 31, 2001 and fromsince that date, Marathon has only one class of common stock authorized.

        On June 30, 2005, we acquired the 38 percent ownership interest in Marathon Ashland Petroleum LLC (“MAP”("MAP") previously held by Ashland Inc. (“Ashland”("Ashland"). In addition, we acquired a portion of Ashland’sAshland's Valvoline Instant Oil Change business, its maleic anhydride business, its interest in LOOP LLC which owns and operates the only U.S. deepwater oil port, and its interest in LOCAP LLC which owns a crude oil pipeline. As a result of the transactions (the “Acquisition”"Acquisition"), MAP is now wholly owned by Marathon and its name was changed to Marathon Petroleum Company LLC (“MPC”("MPC") effective September 1, 2005.


Segment and Geographic Information

        Our operations consist of three operating segments: 1) Exploration and Production (“("E&P”&P") – explores for, produces and producesmarkets crude oil and natural gas on a worldwide basis; 2) Refining, Marketing and Transportation (“("RM&T”&T") – refines, markets and transports crude oil and petroleum products, primarily in the Midwest, the upper Great Plains and southeastern United States; and 3) Integrated Gas (“IG”("IG") – markets and transports natural gas and products manufactured from natural gas, such as liquefied natural gas (“LNG”("LNG") and methanol, on a worldwide basis.basis, and is developing other projects to link stranded natural gas resources with key demand areas. For operating segment and geographic financial information, see Note 89 to the consolidated financial statements.

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Exploration and Production

        (In the discussion that follows regarding our exploration and production operations, references to “net”"net" wells, production or sales indicate our ownership interest or share, as the context requires.)

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     As of December 31, 2005 we were conducting        We conduct exploration, development and production activities in nine countries.ten countries, with a focus on international growth while continuing to maintain our position in the United States. Principal exploration activities were in the United States, Norway, Angola Equatorial Guinea, the United Kingdom and Canada.Indonesia. Principal development and production activities were in the United States, the United Kingdom, Ireland, Norway, Equatorial Guinea Gabon and Russia.
     On December 29, 2005, in conjunction with our partners in the former Oasis Group, we entered into an agreement with the National Oil Corporation of Libya on the terms under which the companies would return to their oil and natural gas exploration and production operations in the Waha concessions in Libya. See Note 5 to the consolidated financial statements.

        Our 20052006 worldwide net liquid hydrocarbon sales from continuing operations averaged 191,000223 thousand barrels per day (“bpd”("mbpd"), an increase of 1236 percent from 20042005 levels. Our 20052006 worldwide net natural gas sales, including natural gas acquired for injection and subsequent resale, averaged 932847 million cubic feet per day (“mmcfd”("mmcfd"), a decrease of 79 percent compared to 2004.2005. In total, our 20052006 worldwide net sales from continuing operations averaged 346,000365 thousand barrels of oil equivalent (“boe”("mboe") per day, compared to 337,000 boe319 mboe per day in 2004.2005. (For purposes of determining boe, natural gas volumes are converted to approximate liquid hydrocarbon barrels by dividing the natural gas volumes expressed in thousands of cubic feet (“mcf”("mcf") by six. The liquid hydrocarbon volume is added to the barrel equivalent of natural gas volume to obtain boe.) In 2006,2007, our worldwide net production available for sale is expected to average approximately 365,000390 to 395,000 boe425 mboe per day, including 40,000 to 45,000 bpd from our Libya operations, excluding future acquisitions and dispositions.

        The above projections of 2006 Libya and2007 worldwide net liquid hydrocarbon and natural gas sales and production available for sale volumes are forward-looking statements. Some factors that could potentially affect timing and levels of production available for sale include pricing, supply and demand for petroleum products, the amount of capital available for exploration and development, regulatory constraints, production decline rates of mature fields, timing of commencing production from new wells, drilling rig availability, inability to or delay in obtaining necessary government and third-party approvals and permits, unforeseen hazards such as weather conditions, acts of war or terrorist acts and the governmentgovernmental or military response, thereto, and other geological, operating and economic considerations. These factors (among others) could cause actual results to differ materially from those set forth in the forward-looking statements.

Exploration

        In the United States during 2005,2006, we drilled 33 gross (21(16 net) exploratory wells of which 2921 gross (18(10 net) wells encountered commercial quantities of hydrocarbons. Of these 2921 wells, one6 gross (zero(4 net) well waswells were temporarily suspended.suspended or were in the process of completing at year end. Internationally, we drilled 1321 gross (six(4 net) exploratory wells of which 1116 gross (five(3 net) wells encountered commercial quantities of hydrocarbons. Of these 1116 wells, 9 gross (five(3 net) wells all were temporarily suspended or arewere in the process of completing.

being completed at December 31, 2006.

United States  –  The Gulf of Mexico continues to be a core area for us with the potential to add new reserves.us. At the end of 2005,2006, we had interests in 129 blocks in the Gulf of Mexico, including 96100 in the deepwater area.

        During 2006, we increased our interest from 20 percent to 30 percent in the Stones prospect (Walker Ridge Block 508). An appraisal well is planned for 2007 on this outside-operated 2005 discovery.

        In 2001, a successful discovery well was drilled on the Ozona prospect (Garden Banks blockBlock 515) in the Gulf of Mexico and, in 2002, two sidetrack wells were drilled, one of which was successful. Our plansWe are continuing to evaluate options to develop this as a subsea tieback to area infrastructure.the Ozona prospect. Commercial terms have been secured for the tiebacktie-back and processing of Ozona production and we are attempting to securehave been actively searching for a drilling rig to drill the development well. We hold a 68 percent operated interest in the Ozona prospect.

        A well on the Flathead prospect (Walker Ridge blockBlock 30) in the Gulf of Mexico was suspended in 2002. Technical evaluations are complete and commercial evaluations continued during 2005in 2006. The drilling of this prospect is delayed due to the shortage of available deepwater rigs. We continue to pursue partnering opportunities with other oil and are progressing towards a possible re-entry and sidetrack before 2008. In 2005, a well drilled on a block directly offsetting the Flathead prospect encountered hydrocarbons.gas companies that have deepwater rigs under contract. We hold a 100 percent operated interest in the Flathead prospect.

     In 2005, we drilled a well on the Stones prospect located on Walker Ridge block 508 in the Gulf of Mexico to total depth and encountered hydrocarbons. Additional drilling is required to determine the commerciality of this prospect. We hold a 20 percent outside-operated interest in the Stones prospect.
     Other United States exploration activity during 2005 included three gross (three net) wells in the Cook Inlet area of Alaska, all of which were discoveries, and 14 gross (six net) wells in the Anadarko Basin in Oklahoma, 13 gross (six net) of which were discoveries.

Norway  –  We hold interests in over 1 million700,000 gross acres offshore Norway and plan to continue our exploration effort there. In late 2005,2006, we began drilling anparticipated in a successful appraisal well aton the outside-operated Gudrun discovery, which we expect will be completed infield, located 120 miles off the first quarter of 2006 and followed by an evaluation of the well results.

     Results for the Volund well (formerly Hamsun) are being analyzed and development scenarios are being examined includingcoast. Marathon holds a possible tie-back to the Alvheim development. We own a 6528 percent outside-operated interest in Volund and serve as operator.
Gudrun where we are primarily focused on evaluating development scenarios.

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Angola  –  Offshore Angola, we ownhold a 10 percent outside-operated interest in Block 31 and a 30 percent outside-operated interest in Block 32. To dateThrough February 2007, we have announced 1320 discoveries on these blocks. We have

3



also participated in four wells that have reached total depth, the results of which will be announced upon government and partner approvals. We expect to participate in 10 or 11 wells on these blocks which reinforces the potential of this trend.in 2007.

        On Block 31, we have four previously announced discoveries which(Plutao, Saturno, Marte and Venus) and one successful appraisal well form a potentialplanned development area in the northeastern portion of the block (Plutao, Saturo, Marte and Venus). In 2005,block. Also on Block 31, we announcedhad five additionalpreviously announced discoveries located in the southeastern partportion of Block 31the block (Palas, Ceres, Juno, Astraea and Hebe). In 2006 and early 2007, we announced discoveries at Urano, Titania, Terra and an unnamed well. We are integrating the results of these wells with our previously announced discoveries.

On Block 32, we previously announced the Gindungothree discoveries (Gindungo, Canela and Canela discoveries.Gengibre). In 2005,2006, we announced the Gengibrefourth discovery on Block 32, the Mostarda-1, and also had a successful appraisaldeepwater delineation well, on this discovery. Lastly,Gengibre-2. We also announced that hydrocarbons were encountered in the Salsa well, but additional drilling is required to assess its commerciality. In early 2006,2007, we announced another discovery ontwo additional discoveries, the Mostarda prospect. Continued exploration success reinforces the potential forManjericao and Caril wells. These discoveries move Block 32 closer toward establishment of a commercial development on Block 32.

development.

Equatorial Guinea  –  During 2004, we participated in two natural gas and condensate discoveries on the Alba Block offshore Equatorial Guinea. The Deep Luba discovery well, drilled from the Alba field production platform, encountered natural gas and condensate in several pay zones. The Gardenia discovery well is located approximately 11 miles southwest of the Alba Field. We are currently evaluating development scenarios for both the Deep Luba and Gardenia discoveries. These discoveries reinforce the potential of the Alba Block, in which we ownWe hold a 63 percent interest.

operated interest in the Alba Block.

        In 2003,2004, we announced a natural gas discoverythe results of the Corona well drilled on Block D offshore Equatorial Guinea, where we are the operator with a 90 percent working interest. The discoveryCorona well is on the Bococo prospect, which is approximately six miles westconfirmed an extension of the Alba field. The well has been suspendedfield on to Block D. An application for re-entryan Area of Commercial Discovery was submitted prior to the end of the production sharing contract's exploration period, which expired at a later date. Development scenarios for the Bococo gas discovery alongend of 2006. We are currently in discussions with three earlier dry gas discoveries onthe Equatorial Guinea government regarding our rights to develop the Block D are being considered for further development.

extension of the Alba Field.

        Libya  –  We hold a 16 percent outside-operated interest in the Waha concessions, which encompass almost 13 million acres located in the Sirte Basin. Our exploration program in 2006 included the drilling of 12 wells, nine of which were successful. Most of these discoveries extended previously defined hydrocarbon accumulations.

Canada  –  We are the operator and own a 30 percent interest in the Annapolis lease offshore Nova Scotia.Scotia, where we continue to evaluate further drilling. In addition,late 2006, we operatedecided to withdraw from the adjacent Cortland lease, where we ownhold a 75 percent interest, and the adjacent Empire lease, where we ownhold a 50 percent interest.

As a result of this withdrawal, a charge equal to 25 percent of the remaining work commitment, or $47 million, was recorded as exploration expense in 2006 and the cash payment will be due to the Canadian provincial government in 2007.

        Indonesia  –  We are the operator and hold a 70 percent interest in the Pasangkayu Block offshore Indonesia. The 1.2 million acre block is located mostly in deep water, predominantly offshore of the island of Sulawesi in the Makassar Strait, directly east of the Kutei Basin oil and natural gas production region. The production sharing contract with the Indonesian government was signed in 2006. We expect to begin collecting geophysical data in 2007, followed by exploratory drilling in 2008 and 2009.

Production (including development activities)

United States  –  Approximately 40Our U.S. operation accounted for 34 percent of our 20052006 worldwide net liquid hydrocarbon sales from continuing operations and 6263 percent of our worldwide net natural gas sales were produced from U.S. operations.

sales.

        During 2005,2006, our productionnet sales in the Gulf of Mexico averaged 33,800 bpd35 mbpd of liquid hydrocarbons, representing 4446 percent of our total U.S. net liquid hydrocarbon sales, and 8443 mmcfd of natural gas, representing 148 percent of our total U.S. net natural gas sales. Net liquid hydrocarbon productionsales in the Gulf of Mexico decreased by 1,900 bpd and net natural gas production decreased by 16 mmcfdincreased slightly from the prior year. The decrease in production isyear, mainly due to natural field declines and the effects of five tropical storms or storms/hurricanes duringin 2005. In September 2004, our Petronius platform suffered damageNet natural gas sales decreased by 41 mmcfd from Hurricane Ivan and was outthe prior year primarily because natural gas sales from the Camden Hills field ended in early 2006 as a result of service until March 2005.increased water production. At year-end 2005,2006, we held interests in eightseven producing fields and seveneight platforms in the Gulf of Mexico, of which four platforms are operated by Marathon.

        The majority of our sales in the Gulf of Mexico comes from the Petronius development in Viosca Knoll Blocks 786 and 830. We own a 50 percent outside-operated interest in these blocks. The platform provides processing and transportation services to adjacent third-party fields. For example, Petronius processes the production from our Perseus field which commenced production in April 2005 and is located five miles from the platform.

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        We hold a 30 percent outside-operated interest in the Neptune deepwater development on Atwater Valley Blocks 573, 574, 575, 617 and 618 in the Gulf of Mexico, 120 miles off the coast of Louisiana. The initial development plan for Neptune was sanctioned in 2005 and includes seven subsea wells tied back to a stand-alone mini-tension leg platform. Construction of the platform and facility continued through 2006 with first production expected in early 2008.

        We are one of the largest natural gas producers in the Cook Inlet and adjacent Kenai Peninsula of Alaska. In 20052006, our Alaskan net natural gas sales averaged 167156 mmcfd, representing 29 percent of our total U.S. net natural gas sales. Our natural gas productionsales from Alaska isare seasonal in nature, trending down during the second and third quarters of each year and increasing during the fourth and first quartersquarters. In May 2006, upon receipt of regulatory approvals, we began to produce and store natural gas in a partially depleted reservoir in the Kenai natural gas field. The natural gas in storage will be used to manage supplies to meet local market winter demands.contractual demand. In addition to our operations in other established Alaskan fields, production from the Ninilchik field began in 2003 and development continues on the field. Ninilchik natural gas is transported through the32-mile 35-mile portion of the Kenai Kachemak Pipeline which connects Ninilchik to the existing natural gas pipeline infrastructure serving residential, utility and industrial markets on the Kenai Peninsula, in Anchorage and in other parts of south central Alaska. We operate Ninilchik and own a 60 percent interest in it and the section of the Kenai Kachemak Pipeline described above. Our 20052006 development program in the Cook Inlet included participation in the drilling of sixseven wells.

        Net liquid hydrocarbon sales from our Wyoming fields averaged 20,700 bpd21 mbpd in 2005 compared to 21,200 bpd in 2004.2006 and 2005. Net natural gas sales from our Wyoming fields averaged 104119 mmcfd in 20052006 compared to 108107 mmcfd in 2004.2005. The decreaseincrease in our Wyoming net natural gas sales is primarily attributed to lower productionhigher net sales from the Powder River Basin, which averaged 77 mmcfd in 2006 compared to 66 mmcfd in 2005 compared to 69 mmcfd in 2004 primarily as a result of natural field decline, partially offset by development drilling.2005 drilling activity. Development of the Powder River Basin continued in 20052006 with approximately119 wells drilled, which was down from the 195 wells drilled comparedin 2005 due to approximately 230 wells drilled in 2004. Water discharge regulations impacted the pace of development in the Powder River Basin in 2005.project delays primarily caused by regulatory and produced water management issues. Additional development of our southwest Wyoming interests continued in 20052006 where we participated in the drilling of 3527 wells.

        Net natural gas sales from our Oklahoma fields averaged 87 mmcfd in 2006 compared to 77 mmcfd in 2005 compared to 82 mmcfd in 2004 primarily as a result of natural field decline, partially offset by development and exploratory drilling. Our 20052006 development program continued to focus in the Anadarko Basin where we participated in the drilling of 8275 wells.

4        Net natural gas sales from our east Texas and north Louisiana fields averaged 71 mmcfd in 2006 compared to 75 mmcfd in 2005. This decrease is primarily attributable to sour gas handling capacity limits at the natural gas plants that purchase our east Texas natural gas, partially offset by development drilling results. Active development of the Mimms Creek field in east Texas continued in 2006.


     Our share of        Net liquid hydrocarbon sales from the Permian Basin region, which extends from southeast New Mexico to west Texas, averaged 15,900 bpd14 mbpd in 2005,2006 compared to 18,900 bpd16 mbpd in 2004. Net natural gas sales from our New Mexico fields, primarily the Indian Basin field, averaged 59 mmcfd in 2005 compared to 85 mmcfd in 2004. These decreases2005. This decrease in net sales arewas due to natural field declines.
     Net natural gas sales from our Texas fields, primarily located in East Texas, averaged 73 mmcfd in 2005 compared to 65 mmcfd in 2004. This increase is primarily attributable to drillingdeclines partially offset by development project results in the PearwoodIndian Basin and Giddings fields.Drinkard areas of southeast New Mexico.

        In addition, active development of the Mimms Creek field in East Texas continued in 2005.

     During 2005, we announced the sanctioning of the Neptune deepwater development on Atwater Valley Blocks 573, 574, 575, 617 and 618 in the Gulf of Mexico. In 2004, we announced that the Neptune 7 appraisal well encountered hydrocarbons. This discovery followed the Neptune 3 discovery in 2002 and the Neptune 5 discovery in 2003. Two successful appraisal sidetrack wells were also drilled from the original Neptune 5 location. We hold a 30 percent interest in the Neptune unit which is located approximately 120 miles off the coast of Louisiana. The field will be developed with seven initial subsea wells tied back to a stand alone tension leg platform. Fabrication of the platform commenced in late 2005. The drilling and completion of the development wells is expected to begin during the first half of 2006. Neptune2006, we completed leasehold acquisitions totaling approximately 200,000 acres in the Bakken Shale oil play. The majority of the acreage is expectedlocated in North Dakota with the remainder in eastern Montana. We now own a substantial position in the Bakken Shale with approximately 300 locations to beginbe drilled over the next five years. Our initial focus has been to evaluate our leasehold position.

        In July 2006, we completed a natural gas leasehold acquisition in the Piceance Basin of Colorado, located in Garfield County in the Greater Grand Valley field complex. The acreage is located near adjacent production. Our plans include drilling approximately 700 wells over the next ten years with first production expected in late 2007 or early 2008 reaching full production during 2008.

     In 2003, we announced the Perseus discovery located on Viosca Knoll Block 8302007.

        We continue to assess our acreage position in the Gulf of MexicoBarnett Shale gas play in north central Texas. To date, we have leased approximately 85,000 net acres in two counties. One core well and five miles from the Petronius platform. Production from the initial development well at Perseushorizontal wells have been drilled and completion activity is underway on these first wells. Seismic data was expected to beginacquired in 2004 but, due to hurricane activity in September 2004 and the resulting damage to the Petronius platform, production was delayed. The initial long-reach development well was drilled from the Petronius platform reaching a total depth of 30,855 feet, and first production commenced in April 2005. Drilling of a second long-reach development well began in September 20052006 and is expected to reach the planned total depth of 31,598 feet in the first quarter of 2006. First production from this second well is anticipated in the second quarter of 2006. We own a 50 percent outside-operated interest in this block.

being evaluated.

United Kingdom  –  Our largest asset in the U.K. sector of the North Sea is the Brae area complex where we are the operator and have a 42 percent interest in the South, Central, North and West Brae fields and a 38 percent interest in the East Brae field. The Brae A platform and facilities host the underlying South Brae field and the adjacent Central Brae field and West Brae/SedgwickBrae fields. The North Brae field, which is produced via the Brae B platform, and the East Brae field are gas condensate fields. Our share of sales from the Brae area averaged 18,300 bpd15 mbpd of liquid hydrocarbons in 2005,2006, compared with 15,900 bpd18 mbpd in 2004. The increase2005. This reduction primarily resulted from West Brae field decline and the timing of sales of liquid hydrocarbons and improved performance from the West Brae reservoir.hydrocarbons. Our share of Brae natural gas sales averaged 169151 mmcfd, which was lower than the 197169 mmcfd in 20042005 as a result of natural field declines in the North and East Brae gas condensate fields.

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        The strategic location of the Brae platforms along with pipeline and onshore infrastructure has generated third-party processing and transportation business since 1986. Currently, there are 23 agreements with28 third-party fields contracted to use the Brae system. In addition to generating processing and pipeline tariff revenue, this third-party business also has a favorable impact on Brae area operations by optimizing infrastructure usage and extending the economic life of the complex.

        The Brae group owns a 50 percent interest in the outside-operated Scottish Area Gas Evacuation (“SAGE”("SAGE") system. The Beryl group owns the remaining 50 percent. The SAGE pipeline transports gas from the Brae and the third-party Beryl areas and has a total wet natural gas capacity of approximately 1.1 billion cubic feet (“bcf”("bcf") per day. The SAGE terminal at St. Fergus in northeast Scotland processes natural gas from the SAGE pipeline and 0.8almost 1 bcf per day of third-party natural gas from the third-party Britannia field.

        In the U.K. Atlantic Margin, we own an approximate 30 percent interest in the outside-operated Foinaven area complex, consisting of a 28 percent interest in the main Foinaven field, 47 percent of East Foinaven and 20 percent of the T35 and T25 accumulations, each of which has a single well.accumulations. Our share of sales from the Foinaven fields averaged 16,000 bpd17 mbpd of liquid hydrocarbons and 910 mmcfd of natural gas in 2005,2006, compared to 21,900 bpd16 mbpd and 109 mmcfd in 2004,2005, primarily as a result of increased liquid handling capacity following facility modifications, increased well potential and improved operating efficiency.

        Norway  –  Norway is a strategic and growing core area, which complements our long-standing operations in the timingU.K. sector of sales ofthe North Sea discussed above. We were approved for our first operatorship on the Norwegian continental shelf in 2002, where today we operate seven licenses.

        During 2006, net liquid hydrocarbons; however, reliability issueshydrocarbon and natural gas sales in Norway from the Heimdal, Vale and Skirne fields averaged 2 mbpd and 36 mmcfd. We own a 24 percent outside-operated interest in the Heimdal field, declines also contributed toa 47 percent outside-operated interest in the decrease.

Norway –Vale field and a 20 percent outside-operated interest in the Skirne field.

        We are the operator and own a 65 percent interest inof the Alvheim complex located on the Norwegian Continental Shelf. This development is comprised of the Kameleon and Kneler and Boa discoveries, in which we have a 65 percent interest, and the previously undeveloped Kameleon accumulation.Boa discovery, in which we have a 58 percent interest. During 2004, we received approval from the Norwegian authorities for our Alvheim plan offor development and operation (“PDO”("PDO"), which will consist of a floating production, storage and offloading vessel (“FPSO”("FPSO") with subsea infrastructure for five drill centers and associated flow lines. The PDO also outlines transportation of produced oil by shuttle tanker and transportation of produced natural gas to the SAGE system using a new14-inch,24-mile 14-inch, 24-mile cross border pipeline. Marathon and its Alvheim project partners signed a purchase and sale agreement in 2004 foracquired the Odin multipurpose shuttle tanker which will beearly in 2005. The vessel is currently being modified to serve as an FPSO.FPSO and has been renamed "Alvheim." In 2004,

5


the Alvheim partners reached agreement to tie-in the nearby Vilje discovery, in which we own a 47 percent outside-operated interest, subject to the approval of the Norwegian government. In 2005, the Norwegian government approved the Vilje PDO. Our shareProgress also continues on the Vilje project, where the subsea preparation is 98 percent complete and development drilling is expected to commence in the second quarter of 2007. First production from a combinedthe Alvheim/Vilje development is expected to reach more than 50,000 boe per day withduring the second quarter of 2007. Four wells will be available at first production startingand drilling activities will continue into 2008. A peak net rate of approximately 75,000 boepd is expected in early 2008.

        In 2006, we submitted a PDO for the Volund field to the Norwegian government, with a recommendation that the field be developed as a subsea tie-back to the Alvheim FPSO. In December 2006, the Ministry of Petroleum and Energy forwarded the PDO to the Norwegian King in Council for approval. Approval was received in early 2007.

     During 2005, net liquid hydrocarbon The Volund development will include three producing wells and a water injection well. The crude oil production will be exported via the shuttle tankers discussed above and the associated natural gas saleswill be exported via the Alvheim-to-SAGE pipeline. The Volund development, in Norway from the Heimdal, Vale, Byggve and Skirne fields averaged 2,000 bpd and 34 mmcfd. Wewhich we own a 2465 percent interest and serve as operator, is expected to begin production in the Heimdal field, a 47 percent interest in the Vale field and a 20 percent interest in the Skirne field, which came on stream during 2004.
second quarter of 2009.

Ireland  –  We own a 100 percent interest in the Kinsale Head, Ballycotton and Southwest Kinsale fields in the Celtic Sea offshore Ireland. Net natural gas sales were 50 mmcfd in 2005, compared with 58 mmcfd in 2004. In February 2006, we acquired an 86.587 percent operated interest in the Seven Heads natural gas field. Previously, we processed and transported natural gas and we provided field operating services to the Seven Heads group through our existing Kinsale Head facilities.

Net natural gas sales in Ireland were 46 mmcfd in 2006, compared with 50 mmcfd in 2005. In June 2006, we were awarded the first commercial natural gas storage license in Ireland, which allows us to provide full third-party storage services from the Southwest Kinsale field. In 2006, we began to produce and hold in storage natural gas from the Kinsale Head field for future delivery under a contract that expires in March 2009. Additionally, natural gas produced from our other fields or purchased from other parties can be stored at Southwest Kinsale for future sale to customers.

        We own an 18.5a 19 percent interest in the outside-operated Corrib natural gas development project, located approximately 40 miles off Ireland’s west coast.Ireland's northwest coast, where five of the seven wells necessary to develop the field have been drilled. During 2004,

6



An Bord Pleanála (the Planning Board) upheld the Mayo County Council’sCouncil's decision to grant planning approval for the proposed natural gas terminal at Bellanaboy Bridge, County Mayo, which will process natural gas from the Corrib field. Development activities started in late 2004 but were suspended in 2005 pending resolutionto facilitate dialogue and clarification of issues raised by opponents of the project. AIn July 2006, the partners in this project accepted the findings of a government-commissioned independent safety review and the report of an independent mediator regarding the onshore pipeline associated with the proposed development has been completeddevelopment. The onshore pipeline will be re-routed and werouting studies are awaiting publicationunderway. Construction of the related report.

natural gas plant re-commenced in the third quarter of 2006. First production from the field is expected in 2009.

Equatorial Guinea  –  We own a 63 percent operated interest in the Alba field offshore Equatorial Guinea and a 52 percent interest in an onshore liquefied petroleum gas ("LPG") processing plant held through an equity method investee. During 2005,2006, net liquid hydrocarbon sales averaged 39,600 bpd48 mbpd and net natural gas sales averaged 9268 mmcfd, compared to 18,900 bpd40 mbpd and 7692 mmcfd in 2004.2005. A condensate expansion project in Equatorial Guinea was completed during 2004 and ramped up to full production and a new, larger LPG plant was completed in early 2005. This expansion project increasedNet sales in 2006 averaged 36 mbpd of condensate production from approximately 15,000 gross bpd to approximately 67,000 gross bpd (38,000 bpd net to Marathon). A liquefied petroleum gas (“LPG”and 12 mbpd of LPG.

        We own 45 percent of Atlantic Methanol Production Company LLC ("AMPCO") expansion project in Equatorial Guinea ramped up to full production, the results of which are included in the third quarter of 2005. Gross LPG production increased from approximately 3,000Integrated Gas segment. In 2006, we supplied a gross bpd to 19,000 gross bpd (11,000 bpd net to Marathon). Liquid hydrocarbon production continues to increase as a result of the expansion projects. Total production available for sale in January 2006 was approximately 90,000 gross bpd (51,000 bpd net to Marathon).

     Approximately 13099 mmcfd of dry gas, remainingwhich remains after the condensate and LPG are removed, is supplied to Atlantic Methanol Production Company LLC (“AMPCO”),AMPCO, where it iswas used to manufacture methanol. We own 45 percent of AMPCO, which is reported in the Integrated Gas segment. Remaining dry gas is returned offshore and reinjected into the Alba reservoir for later production when the LNG plant construction projectproduction facility on Bioko Island, discussed below under Integrated Gas, is completed.

Libya  –  We holdNet liquid hydrocarbon sales in Libya averaged 54 mbpd in 2006, of which a 16.33 percent interest intotal of 8 mbpd were owed to our account upon the Waha concessions, which currently produce approximately 350,000 gross boe per day and encompass almost 13 million acres located in the Sirte Basin. As a resultresumption of our return to operations in Libya. The 2006 sales in Libya we expectrepresented 37 percent of our international liquid hydrocarbon sales from continuing operations. We continue to add approximately 40,000work with our partners to 45,000 net bpd of production availabledefine and implement growth plans for sale during 2006.

this business.

Gabon  –  We are the operator of the Tchatamba South, Tchatamba West and Tchatamba Marin fields offshore Gabon with a 56 percent interest. Net sales in Gabon averaged 12,100 bpd10 mbpd of liquid hydrocarbons in 2005,2006, compared with 13,600 bpd12 mbpd in 2004.2005. Production from these three fields is processed on a single offshore facility at Tchatamba Marin, with processed oil being transported through an offshore and onshore pipeline to an outside-operated storage facility.

Russia  –  During 2003 we acquired Khanty Mansiysk Oil Corporation (“KMOC”). KMOC’swhich operated oil fields are located in the Khanty Mansiysk region of western Siberia. Net liquid hydrocarbon sales from these assets averaged 26,600 bpd during 2005,were primarily from the East Kamennoye and Potenay fields. Development activities continued in 2005, with 82 wells drilled in East Kamennoye.

In June 2006, we sold these Russian oil exploration and production businesses.

Other Matters

        We hold an interest in an exploration and production license in Sudan. We suspended all operations in Sudan in 1985.1985 due to civil unrest. We have had no employees in the country and have derived no economic benefit from those interests since that time. The U.S. government imposed sanctions against Sudan in 1997 and we have not made any payments related to Sudan since then. We have abided and will continue to abide by all U.S. sanctions related to Sudan and will not consider resuming any activity regarding our interests there until such time as it is permitted under U.S. law.

Our intention is to exit this license in 2007.

        We discovered the Ash Shaer and Cherrife gas fields in Syria in the 1980s. We submitted four plans of development tohave recognized no revenues in any period from activities in Syria and we impaired our entire investment in Syria in 1998. In July 2006, the Syrian Petroleum Company in the 1990s, but none were approved. The Syrian government subsequently claimed that thenew production sharing contract forawarded by the Syrian government was signed into law. This contract gave us the right to assign all or part of our interest in these fields had expired. We have been involved in an

6


ongoing dispute withto a third party, subject to the consent of the Syrian government, and also resolved the previous disputes between us, the Syrian Petroleum Company and the Syrian government of Syria over our interest in these fields. We are discussing a settlement under which a new production sharing contract would be executed to provide usIn October 2006, the right to sell all or a significant portionSyrian government approved the assignment of 90 percent of our interest in the Ash Shaer and Cherrife natural gas fields to a third party.non-U.S. company. We haveclosed the transaction on November 1, 2006, and willreceived cash proceeds of $46 million. While we continue to hold a 10 percent outside-operated interest, we continue to comply with all U.S. sanctions related to Syria.
We expect to sell the remaining 10 percent interest in 2007.

        The above discussion of the E&P segment includes forward-looking statements with respect to the timing of completion of the Gudrun appraisal well,anticipated future exploratory and development drilling, the possibility of developing the Gudrun field offshore Norway and Blocks 31 and 32 offshore Angola, the timing and levels of production from the Neptune development, the Perseus discovery,Piceance Basin, the combined Alvheim/Vilje development, the Volund field and estimated levels of production associated with our re-entry into Libya.the Corrib project. Some factors which could potentially affect the timing of completion of the Gudrun appraisal well, the possible development of Blocks 31 and 32, the timing and production levels of the Neptune development, the Perseus discovery, the Alvheim/Vilje development and estimated levels of production in Libyathese forward-looking statements include pricing, supply and demand for petroleum products, the amount of capital available for exploration and development, regulatory constraints, drilling rig availability, inability or delays in obtaining necessary government or third-party approvals or permits, timing of commencing production from new wells, unforeseen hazards such as weather conditions, acts of war or terrorist acts and the governmental or military response, and other geological, operating and

7



economic considerations. The estimated levels of productionExcept for the Alvheim/Vilje and Volund developments, the foregoing forward-looking statements may be further affected by the inability to obtain or delay in Libyaobtaining necessary government and third-party approvals and permits. The possible developments inon the Gudrun field and Blocks 31 and 32 could further be affected by presently known data concerning size and character of reservoirs, economic recoverability, future drilling success and production experience. The foregoing factors (among others) could cause actual results to differ materially from those set forth in the forward-looking statements.

7Reserves


Reserves
        At December 31, 2005,2006, our net proved liquid hydrocarbon and natural gas reserves totaled approximately 1.2951.262 billion boe, of which 44approximately 40 percent were located in Organization for Economic Cooperation and Development (“OECD”("OECD") countries. The following table sets forth estimated quantities of net proved oil and natural gas reserves at the end of each of the last three years.


Estimated Quantities of Net Proved Liquid Hydrocarbon and Natural Gas Reserves at December 31

                           
    Developed and
  Developed Undeveloped
     
  2005 2004 2003 2005 2004 2003
 
Liquid Hydrocarbons(Millions of Barrels)
                        
 United States  165   171   193   189   191   210 
 Europe  39   41   47   98   107   59 
 Africa  368   147   120   373   223   218 
 Other International  31   27   31   44   39   89 
                   
  Total Consolidated  603   386   391   704   560   576 
 Equity Method Investees  –    –    2   –    –    2 
                   
WORLDWIDE  603   386   393   704   560   578 
                   
Developed reserves as a percent of total net proved reserves  86%  69%  68%            
Natural Gas(Billions of Cubic Feet)
                        
 United States  943   992   1,067   1,209  ��1,364   1,635 
 Europe  326   376   421   486   544   484 
 Africa  638   570   528   1,852   1,564   665 
                   
WORLDWIDE  1,907   1,938   2,016   3,547   3,472   2,784 
                   
Developed reserves as a percent of total net proved reserves  54%  56%  72%            
Total BOE(Millions of Barrels)
                        
 United States  322   336   371   390   418   483 
 Europe  93   104   117   179   198   139 
 Africa  475   242   208   682   484   329 
 Other International  31   27   31   44   39   89 
                   
  Total Consolidated  921   709   727   1,295   1,139   1,040 
 Equity Method Investees  –    –    2   –    –    2 
                   
WORLDWIDE  921   709   729   1,295   1,139   1,042 
                   
Developed reserves as a percent of total net proved reserves  71%  62%  70%            
 

 
 Developed
 Developed and
Undeveloped

 
 2006
 2005
 2004
 2006
 2005
 2004

Liquid Hydrocarbons(Millions of barrels)            
 United States 150 165 171 172 189 191
 Europe 35 39 41 108 98 107
 Africa 381 368 147 397 373 223
  
 
 
 
 
 
Worldwide Continuing Operations 566 572 359 677 660 521
Discontinued Operations(a) –   31 27 –   44 39
  
 
 
 
 
 
WORLDWIDE 566 603 386 677 704 560
  
 
 
 
 
 
Developed reserves as a percent of total net proved reserves 84%86%69%     

Natural Gas
(Billions of cubic feet)

 

 

 

 

 

 

 

 

 

 

 

 
 United States 857 943 992 1,069 1,209 1,364
 Europe 238 326 376 444 486 544
 Africa 648 638 570 1,997 1,852 1,564
  
 
 
 
 
 
WORLDWIDE 1,743 1,907 1,938 3,510 3,547 3,472
  
 
 
 
 
 
Developed reserves as a percent of total net proved reserves 50%54%56%     
Total BOE(Millions of barrels)            
 United States 293 322 336 350 390 418
 Europe 75 93 104 182 179 198
 Africa 489 475 242 730 682 484
  
 
 
 
 
 
Worldwide Continuing Operations 857 890 682 1,262 1,251 1,100
Discontinued Operations(a) –   31 27 –   44 39
  
 
 
 
 
 
WORLDWIDE 857 921 709 1,262 1,295 1,139
  
 
 
 
 
 
Developed reserves as a percent of total net proved reserves 68%71%62%     

(a)
Represents Marathon's Russian businesses, which were sold in 2006.

        Proved developed reserves represented 7168 percent of total proved reserves as of December 31, 2005,2006, as compared to 6271 percent as of December 31, 2004.2005. Of the 374405 million boe of proved undeveloped reserves at year-end 2005,2006, less than 2010 percent of the volume is associated with projects that have been included asin proved reserves for more than three years while approximately 1811 percent of the proved undeveloped reserves were added during 2005.

2006.

        During 2005,2006, we added a total of 146 million boe of net proved reserves, principally in Libya and Equatorial Guinea. We disposed of 28245 million boe, excluding 2 million boe of dispositions, while producing 124 million boe. These net additions included 165 million boe as a result of our re-entry into Libya, 50 million boe of extensions, discoveries and other additions, and total revisions of 58134 million boe. Of the total net proved reserve additions, 21582 million boe were proved developed and 6764 million boe were proved undeveloped. Additionally,undeveloped reserves. During 2006, we transferred 12118 million boe from proved undeveloped to proved developed during 2005.reserves. Costs incurred for the periods ended December 31, 2006, 2005 2004 and 20032004 relating to the development of proved undeveloped oil and natural gas reserves, were $1.010 billion, $955 million and $708 million and $780 million. These amounts include our proportionate share of equity method investees’ costs incurred as these were costs necessary for the development of proved undeveloped reserves. As of December 31, 2005,2006, estimated future development costs relating to the development of proved undeveloped oil and natural gas reserves for the years 20062007 through 20082009 are projected to be $868$466 million, $340$348 million and $175$231 million.

8



     The        Our Libyan fields had the most significant positive changes, totaling 69 million boe. This included positive revisions due to access to additional data and our improved understanding of reservoir performance during the first year after our re-entry and additions for future development drilling. At the end of 2006, our proved reserves associated with Libya totaled 214 million boe, or 17 percent of our total proved reserves. Additionally, 21 million boe were added to our proved reserves for the Alba field in Equatorial Guinea, had the most significant positive revisions, totaling 47 million boe. Of this volume, 21 million boe was added due to the progress on the Equatorial Guinea LNG project, which will provideprimarily as a market for the Alba field’sresult of expanded natural gas reserves soonermarketing and to a greater extent under the current production sharing contract than was expected when proved reserves were estimated at the end of 2004. At the end of 2005, our total proved reserves associated with the Alba field offshore Equatorial Guinea totaled 505 million boe, or 39 percent of our total proved reserves.
supply agreements.

        The above estimated quantities of net proved oil and natural gas reserves and estimated future development costs relating to the development of proved undeveloped oil and natural gas reserves and timing of production from development projects are forward-looking statements and are based on a number of assumptions, including (among others) commodity prices, presently known physical data concerning size and character of the reservoirs, economic recoverability, technology developments, future drilling success, industry economic conditions, levels of cash flow from operations, production experience and other operating considerations. To the extent these assumptions prove inaccurate, actual recoveries and development costs could be different than current estimates.

        For a discussion of the proved reserve estimation process, see Management's Discussion and Analysis of Financial Condition and Results of Operations – Critical Accounting Estimates – Estimated Net Recoverable Quantities of Oil and Natural Gas, and for additional details of the estimated quantities of net proved oil and natural gas reserves at the end of each of the last three years, see “FinancialFinancial Statements and Supplementary Data – Supplementary Information on Oil and Gas Producing Activities – Estimated Quantities of Proved Oil and Natural Gas Reserves”Reserves on pages F-46 through F-47. We filed reports with the U.S. Department of Energy (“DOE”("DOE") for the years 20042005 and 20032004 disclosing the year-end estimated oil and natural gas reserves. We will file a similar report for 2005.2006. The year-end estimates reported to the DOE are the same as the estimates reported in the Supplementary Information on Oil and Gas Producing Activities.

Delivery Commitments

Delivery Commitments

        We have committed to deliver fixed and determinable quantities of natural gas to customers under a variety of contractual arrangements.

        In Alaska, we have two long-term sales contracts with local utility companies, which obligate us to supply approximately 152124 bcf of natural gas over the remaining lives of these contracts, which terminate in 2012 and 2018. During 2005, we entered into another agreement with a local utility company which, pending Regulatory Commission of Alaska approval, will obligate us to supply approximately 60 bcf of natural gas between 2009 and 2018. In addition, we own a 30 percent interest in a Kenai, Alaska LNG plant and a proportionate share of the long-term LNG sales obligation to two Japanese utility companies. This obligation is estimated to total 6243 bcf through the remaining life of the contract, which terminates in 2009. These commitments are structured with variable-pricing terms. Our production from various natural gas fields in the Cook Inlet supply the natural gas to service these contracts. Our proved reserves in the Cook Inlet are sufficient to meet these contractual obligations.

        In the U.K., we have two long-term sales contracts with utility companies, which obligate us to supply approximately 190125 bcf of natural gas through the remaining lives of these contracts, which terminate in 2009. Our Brae area proved reserves, acquired natural gas contracts and estimated production rates are sufficient to meet these contractual obligations. Pricing under these natural gas sales contracts is variable. See Note 1718 to the consolidated financial statements for further discussion of these contracts.

9


Oil and Natural Gas Net Sales

Oil and Natural Gas Net Sales

        The following tables set forth the daily average net sales of liquid hydrocarbons and natural gas for each of the last three years:

years.


Net Liquid Hydrocarbon Sales
(a)(b)

              
(Thousands of Barrels per Day) 2005 2004 2003
 
United States(c)
  76   81   107 
Europe(d)
  36   40   41 
Africa(d)
  52   32   27 
Other International(d)
  27   16   10 
          
 Total Consolidated Continuing Operations  191   169   185 
Equity Method Investees  –    1   6 
          
Worldwide Continuing Operations  191   170   191 
Discontinued Operations(e)
  –    –    3 
          
WORLDWIDE  191   170   194 
          

(Thousands of barrels per day)

 2006
 2005
 2004

United States(b) 76 76 81
Europe(c) 35 36 40
Africa(c) 112 52 32
  
 
 
 Worldwide Continuing Operations 223 164 153
Discontinued Operations(d) 12 27 17
  
 
 
WORLDWIDE 235 191 170
  
 
 


Net Natural Gas Sales
(e)

(Millions of cubic feet per day)

 2006
 2005
 2004

United States(b) 532 578 631
Europe(f) 197 224 273
Africa 72 92 76
  
 
 
WORLDWIDE 801 894 980

(a)
Includes crude oil, condensate and natural gas liquids.
(b)
Represents net sales from leasehold ownership, after royalties and interests of others.
(c)
Represents equity tanker liftings and direct deliveries of liquid hydrocarbons. The amounts correspond with the basis for fiscal settlements with governments. Crude oil purchases, if any, from host governments are excluded.
(d)
Represents Marathon's Russian oil exploration and production businesses that were sold in June 2006.
(e)
Represents net sales after royalties, except for Ireland where amounts are before royalties.
(f)
              
(Millions of Cubic Feet per Day) 2005 2004 2003
 
United States(c)
  578   631   732 
Europe  224   273   262 
Africa  92   76   66 
          
 Total Consolidated Continuing Operations  894   980   1,060 
Equity Method Investees  –    –    13 
          
Worldwide Continuing Operations  894   980   1,073 
Discontinued Operations(e)
  –    –    74 
          
WORLDWIDE  894   980   1,147 
 
(a)Includes crude oil, condensate and natural gas liquids.
(b)Amounts represent net sales after royalties, except for the U.K., Ireland and the Netherlands where amounts are before royalties for the applicable periods.
(c)Amounts represent net sales from leasehold ownership, after royalties and interests of others.
(d)Amounts represent equity tanker liftings and direct deliveries of liquid hydrocarbons. The amounts correspond with the basis for fiscal settlements with governments. Crude oil purchases, if any, from host governments are excluded.
(e)Amounts represent Marathon’s western Canadian operations.
(f)Amounts exclude volumes purchased from third parties for injection and subsequent resale of 38 mmcfd in 2005, 19 mmcfd in 2004 and 23 mmcfd in 2003.
Excludes volumes acquired from third parties for injection and subsequent resale of 46 mmcfd, 38 mmcfd and 19 mmcfd in 2006, 2005 and 2004.

10


Productive and Drilling Wells

10


Productive and Drilling Wells
        The following tables set forth productive wells and service wells for eachas of the last three yearsDecember 31, 2006, 2005 and 2004, and drilling wells as of December 31, 2005.
2006.


Gross and Net Wells

                                 
2005 Productive Wells(a)        
       
      Service Drilling
  Oil Natural Gas Wells(b) Wells(c)
         
  Gross Net Gross Net Gross Net Gross Net
 
United States 5,724   2,029   5,254   3,696   2,723   827   55   31 
Europe 51   19   68   37   29   10   3   1 
Africa 926   155   13   8   97   18   7   1 
Other International 156   156   –    –    50   50   26   26 
                         
WORLDWIDE 6,857   2,359   5,335   3,741   2,899   905   91   59 
                         
                                 
2004 Productive Wells(a)        
         
      Service    
  Oil Natural Gas Wells(b)    
           
  Gross Net Gross Net Gross Net    
                 
United States 5,604   2,022   4,860   3,702   2,749   845         
Europe 54   20   66   35   28   10         
Africa 9   5   13   9   3   1         
Other International 116   116   –    –    23   23         
                         
WORLDWIDE 5,783   2,163   4,939   3,746   2,803   879         
                         
                                  
2003 Productive Wells(a)        
         
      Service    
  Oil Natural Gas Wells(b)    
           
  Gross Net Gross Net Gross Net    
                 
United States 5,580   2,040   4,649   3,555   2,726   834         
Europe 52   14   65   35   27   9         
Africa 7   4   10   7   1   1         
Other International 109   109   –    –    21   21         
                         
 Total Consolidated 5,748   2,167   4,724   3,597   2,775   865         
Equity Method Investees 96   21   –    –    15   3         
                         
WORLDWIDE 5,844   2,188   4,724   3,597   2,790   868         
 
(a)Includes active wells and wells temporarily shut-in. Of the gross productive wells, gross wells with multiple completions operated by Marathon totaled 278 in 2005, 273 in 2004 and 273 in 2003. Information on wells with multiple completions operated by other companies is unavailable to Marathon.
(b)Consists of injection, water supply and disposal wells.
(c)Consists of exploratory and development wells.

 
 Productive Wells(a)
  
  
  
  
 
 Service
Wells
(b)
 Drilling
Wells
(c)
 
 Oil
 Natural Gas
 
 Gross
 Net
 Gross
 Net
 Gross
 Net
 Gross
 Net

2006
                
United States 5,661 2,068 5,554 4,063 2,729 834 39 21
Europe 51 19 75 41 31 12 2 1
Africa 925 155 13 9 100 19 10 2
Other International –   –   –   –   –   –   –   –  
  
 
 
 
 
 
 
 
WORLDWIDE 6,637 2,242 5,642 4,113 2,860 865 51 24
  
 
 
 
 
 
 
 

2005

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
United States 5,724 2,029 5,254 3,696 2,723 827    
Europe 51 19 68 37 29 10    
Africa 926 155 13 8 97 18    
Other International 156 156 –   –   50 50    
  
 
 
 
 
 
    
WORLDWIDE 6,857 2,359 5,335 3,741 2,899 905    
  
 
 
 
 
 
    

2004

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
United States 5,604 2,022 4,860 3,702 2,749 845    
Europe 54 20 66 35 28 10    
Africa 9 5 13 9 3 1    
Other International 116 116 –   –   23 23    
  
 
 
 
 
 
    
WORLDWIDE 5,783 2,163 4,939 3,746 2,803 879    

(a)
Includes active wells and wells temporarily shut-in. Of the gross productive wells, wells with multiple completions operated by Marathon totaled 294, 278 and 273 in 2006, 2005 and 2004. Information on wells with multiple completions operated by others is unavailable to us.
(b)
Consists of injection, water supply and disposal wells.
(c)
Consists of exploratory and development wells.

11


Drilling Activity

11


Drilling Activity
        The following table sets forth, by geographic area, the number of net productive and dry development and exploratory wells completed in each of the last three years:
years.


Net Productive and Dry Wells Completed
(a)

                
    2005 2004 2003
 
United States              
 
Development(b)
 – Oil  46   13   4 
  – Natural Gas  288   167   231 
  – Dry  4   –    –  
            
  Total  338   180   235 
 Exploratory – Oil  2   1   1 
  – Natural Gas  17   8   7 
  – Dry  2   6   2 
            
  Total  21   15   10 
            
  Total United States  359   195   245 
International              
 
Development(b)
 – Oil  68   27   31 
  – Natural Gas  2   3   14 
  – Dry  1   1   1 
            
  Total  71   31   46 
 Exploratory – Oil  2   2   2 
  – Natural Gas  –    –    21 
  – Dry  4   7   5 
            
  Total  6   9   28 
  Total International  77   40   74 
            
WORLDWIDE    436   235   319 
 
(a)Includes the number of wells completed during the applicable year regardless of the year in which drilling was initiated. Excludes any wells where drilling operations were continuing or were temporarily suspended as of the end of the applicable year. A dry well is a well found to be incapable of producing hydrocarbons in sufficient quantities to justify completion. A productive well is an exploratory or development well that is not a dry well.
(b)Indicates wells drilled in the proved area of an oil or natural gas reservoir.
Oil and Natural Gas Acreage

 
 
 2006
 2005
 2004

United States      
 Development(b)- Oil 32 46 13
 - Natural Gas 186 288 167
 - Dry 5 4 –  
   
 
 
 Total 223 338 180
 Exploratory- Oil 3 2 1
 - Natural Gas 8 17 8
 - Dry 3 2 6
   
 
 
 Total 14 21 15
   
 
 
 Total United States 237 359 195
International       
 Development(b)- Oil 51 68 27
 - Natural Gas 1 2 3
 - Dry –   1 1
   
 
 
 Total 52 71 31
 Exploratory- Oil 19 2 2
 - Natural Gas –   –   –  
 - Dry 6 4 7
   
 
 
 Total 25 6 9
 Total International 77 77 40
   
 
 
 WORLDWIDE 314 436 235

(a)
Includes the number of wells completed during the applicable year regardless of the year in which drilling was initiated. Excludes any wells where drilling operations were continuing or were temporarily suspended as of the end of the applicable year. A dry well is a well found to be incapable of producing hydrocarbons in sufficient quantities to justify completion. A productive well is an exploratory or development well that is not a dry well.
(b)
Indicates wells drilled in the proved area of an oil or natural gas reservoir.

Oil and Natural Gas Acreage

        The following table sets forth, by geographic area, the developed and undeveloped oil and natural gas acreage that we held as of December 31, 2005:

2006.


Gross and Net Acreage

                         
      Developed and
  Developed Undeveloped Undeveloped
       
(Thousands of Acres) Gross Net Gross Net Gross Net
 
United States  1,459   910   2,894   1,415   4,353   2,325 
Europe  395   305   968   393   1,363   698 
Africa  12,971   2,149   2,951   769   15,922   2,918 
Other International  599   599   2,541   1,997   3,140   2,596 
                   
WORLDWIDE  15,424   3,963   9,354   4,574   24,778   8,537 
 

 
 Developed
 Undeveloped
 Developed and Undeveloped
(Thousands of Acres)

 Gross
 Net
 Gross
 Net
 Gross
 Net

United States 1,183 733 2,813 1,366 3,996 2,099
Europe 467 367 972 401 1,439 768
Africa 12,977 2,150 2,901 745 15,878 2,895
Other International –   –   2,577 1,684 2,577 1,684
  
 
 
 
 
 
 WORLDWIDE 14,627 3,250 9,263 4,196 23,890 7,446

12



Refining, Marketing and Transportation

        Our RM&T operations are primarily conducted by MPC and its subsidiaries, including its wholly-owned subsidiaries Speedway SuperAmerica LLC (“SSA”("SSA") and Marathon Pipe Line LLC.

Refining

        We own and operate seven refineries with an aggregate refining capacity of 974,000 barrels974 mbpd of crude oil. During 2006, our refineries processed 980 mbpd of crude oil per day.and 234 mbpd of other charge and blend stocks for a crude oil capacity utilization rate of 101 percent. The table below sets forth the location and daily throughput capacity of each of our refineries as of December 31, 2005:

2006.

Crude Oil Refining Capacity
(Thousand Barrels per Day)
  
Crude Oil Refining Capacity
(Barrels per Day)

Garyville, Louisiana

 
245,000
245
Catlettsburg, Kentucky 222,000222
Robinson, Illinois 192,000192
Detroit, Michigan 100,000100
Canton, Ohio 73,00073
Texas City, Texas 72,00072
St. Paul Park, Minnesota 70,00070
  
TOTAL 974,000974
  

        Our refineries include crude oil atmospheric and vacuum distillation, fluid catalytic cracking, catalytic reforming, desulfurization and sulfur recovery units. The refineries can process a wide variety of crude oils and produce typical refinery products, including reformulated and low sulfur gasolines.gasolines and ultra-low sulfur diesel fuel. We also produce asphalt cements, polymerized asphalt, asphalt emulsions and industrial asphalts. We manufacture petroleum pitch, primarily used in the graphite electrode, clay target and refractory industries. Additionally, we manufacture aromatics, aliphatic hydrocarbons, cumene, base lube oil, polymer grade propylene, maleic anhydride and slack wax.

        Our refineries are integrated via pipelines, terminals and barges to maximize operating efficiency. The transportation links that connect theour refineries allow the movement of intermediate products to optimize operations and the production of higher margin products. For example, naphtha may be moved from Texas City to Robinson where excess reforming capacity is available. By shipping intermediate products between facilities during partial refinery shutdowns, we are able to utilize processing capacity that is not directly affected by the shutdown work.

     We increased our overall crude oil refining capacity during 2005 from 948,000 bpd to 974,000 bpd after completing the expansion project at our Detroit refinery. This expansion increased crude oil capacity at Detroit from 74,000 bpd to 100,000 bpd. The project also improves operating efficiency and enables the Detroit refinery to meet new lower gasoline and diesel sulfur specifications.
     During 2005, we announced plans to evaluate a 180,000 bpd expansion of our Garyville refinery. The initial phase of the potential expansion includes front-end engineering and design (“FEED”) work which began in December 2005 and could lead to the start of construction in 2007. The project, estimated to cost approximately $2.2 billion, could be completed as early as the fourth quarter of 2009. The final investment decision is subject to completion of the FEED work and the receipt of applicable permits.
     We also produce asphalt cements, polymerized asphalt, asphalt emulsions and industrial asphalts. We manufacture petroleum pitch, primarily used in the graphite electrode, clay target and refractory industries. Additionally, we manufacture aromatics, aliphatic hydrocarbons, cumene, base lube oil, polymer grade propylene, maleic anhydride and slack wax.
     During 2005, our refineries processed 973,000 bpd of crude oil and 205,000 bpd of other charge and blend stocks. The following table sets forth our refinery production by product group for each of the last three years:
Refined Product Yields
             
(Thousands of Barrels per Day) 2005 2004 2003
 
Gasoline  644   608   567 
Distillates  318   299   284 
Propane  21   22   21 
Feedstocks and Special Products  96   94   93 
Heavy Fuel Oil  28   25   24 
Asphalt  85   77   72 
          
TOTAL  1,192   1,125   1,061 
 

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        Planned maintenance activities requiring temporary shutdown of certain refinery operating units, or turnarounds, are periodically performed at each refinery. We completed a major turnaroundsturnaround at our Catlettsburg refinery in 2006.

        The following table sets forth our refinery production by product group for each of the last three years.


Refined Product Yields

(Thousands of Barrels per Day)

 2006
 2005
 2004

Gasoline 661 644 608
Distillates 323 318 299
Propane 23 21 22
Feedstocks and Special Products 107 96 94
Heavy Fuel Oil 26 28 25
Asphalt 89 85 77
  
 
 
TOTAL 1,229 1,192 1,125

        We completed all of our ultra-low sulfur diesel fuel modifications required by the U.S. Environmental Protection Agency prior to its June 1, 2006 deadline. These modifications were completed on time and under budget.

13


        In 2006, our Board of Directors approved a projected $3.2 billion expansion of our Garyville, Louisiana refinery by 180 mbpd to 425 mbpd, which will increase our total refining capacity to 1.154 million barrels per day ("mmbpd"). We recently received air permit approval from the Louisiana Department of Environmental Quality for this project and construction is expected to begin in mid-2007, with startup planned for the fourth quarter of 2009.

        We have also commenced front-end engineering and design ("FEED") for a potential heavy oil upgrading project at our Detroit refinery, which would allow us to process increased volumes of Canadian oil sands production, and are undertaking a feasibility study for a similar upgrading project at our Catlettsburg refineries in 2005.

refinery.

Marketing

        We are a supplier of gasoline and distillates to resellers and consumers within our market area in the Midwest, the upper Great Plains and southeastern United States. In 2005,2006, our refined product sales volumes (excluding matching buy/sell transactions) totaled 21.121.5 billion gallons, (1,378,000 bpd).or 1.401 mmbpd. The average sales price of our refined products in aggregate was $77.76 per barrel for 2006. The following table sets forth our refined product sales by product group and our average sales price for each of the last three years.


Refined Product Sales

(Thousands of Barrels per Day)

 2006
 2005
 2004

Gasoline  804  836  807
Distillates  375  385  373
Propane  23  22  22
Feedstocks and Special Products  106  96  92
Heavy Fuel Oil  26  29  27
Asphalt  91  87  79
  
 
 
TOTAL(a)  1,425  1,455  1,400
  
 
 
Average sales price ($ per barrel) $77.76 $66.42 $49.53

(a)
Includes matching buy/sell volumes of 24 mbpd, 77 mbpd and 71 mbpd in 2006, 2005 and 2004. On April 1, 2006, we changed our accounting for matching buy/sell arrangements as a result of a new accounting standard. This change resulted in lower refined product sales volumes for the remainder of 2006 than would have been reported under the previous accounting practices. See Note 2 to the consolidated financial statements.

        The wholesale distribution of petroleum products to private brand marketers and to large commercial and industrial consumers primarily located in the Midwest, the upper Great Plains and the Southeast, and sales in the spot market accounted for approximately 71 percent of our refined product sales volumes in 2005, excluding sales related to matching buy/sell transactions. Approximately 532006. We sold 52 percent of our gasoline sales volumes and 9189 percent of our distillate salesdistillates volumes were sold on a wholesale or spot market basis.

     Approximately half Half of our propane is sold into the home heating market, with the balance being purchased by industrial consumers. Propylene, cumene, aromatics, aliphatics, and sulfur are domestically marketed to customers in the chemical industry. Base lube oils, maleic anhydride, slack wax, extract and pitch are sold throughout the United States and Canada, with pitch products also being exported worldwide.
We market asphalt through owned and leased terminals throughout the Midwest, the upper Great Plains and the Southeast.southeastern United States. Our customer base includes approximately 830800 asphalt-paving contractors, government entities (states, counties, cities and townships) and asphalt roofing shingle manufacturers.

        We blended 35 mbpd of ethanol into gasoline in 2006. In 2005 and 2004, we blended 35 mbpd and 30 mbpd of ethanol. The following table sets forthexpansion or contraction of our refined product salesethanol blending program will be driven by product group for eachthe economics of the last three years:

Refined Product Sales
             
(Thousands of Barrels per Day) 2005 2004 2003
 
Gasoline  836   807   776 
Distillates  385   373   365 
Propane  22   22   21 
Feedstocks and Special Products  96   92   97 
Heavy Fuel Oil  29   27   24 
Asphalt  87   79   74 
          
TOTAL  1,455   1,400   1,357 
          
Matching Buy/ Sell Volumes included in above  77   71   64 
 
ethanol supply and changes in government regulations. We sell reformulated gasoline in parts of our marketing territory, primarily Chicago, Illinois; Louisville, Kentucky; northern Kentucky; and Milwaukee, Wisconsin. We alsoWisconsin, and we sell low-vapor-pressure gasoline in nine states.

        As of December 31, 2005,2006, we supplied petroleum products to about 4,0004,200 Marathon branded retail outlets located primarily in Ohio, Michigan, Ohio, Indiana, Kentucky and Illinois. Branded retail outlets are also located in Florida, Georgia, Minnesota, Wisconsin, West Virginia, Tennessee, Virginia, North Carolina, Pennsylvania, Alabama and South Carolina.

Sales to Marathon brand jobbers and dealers accounted for 14 percent of our refined product sales volumes in 2006.

        SSA sells gasoline and diesel fuel through company-operated retail outlets. Sales of refined products through these SSA retail outlets accounted for 15 percent of our refined product sales volumes in 2006. As of December 31, 2005,2006, SSA had 1,6381,636 retail outlets in nine states that sold petroleum products and convenience store merchandise and services, primarily under the brand names “Speedway”"Speedway" and “SuperAmerica.” SSA’s"SuperAmerica." SSA's revenues from the sale of non-petroleum merchandise totaled $2.7 billion in 2006, compared with $2.5 billion in 2005, compared with $2.3 billion in 2004.2005. Profit levels from the sale

14



of such merchandise and services tend to be less volatile than profit levels from the retail sale of gasoline and diesel fuel. SSA also operates 60 Valvoline Instant Oil Change retail outlets located in Michigan and northwest Ohio.

        Pilot Travel Centers LLC (“PTC”("PTC"), our joint venture with Pilot Corporation (“Pilot”("Pilot"), is the largest operator of travel centers in the United States with approximately 260269 locations in 37 states and Canada at December 31, 2005.2006. In 2006, PTC expanded internationally with the opening of a site in Ontario, Canada. The travel centers offer diesel fuel, gasoline and a variety of other services, including on-premises brand-name restaurants.restaurants at many locations. Pilot and Marathon each own a 50 percent interest in PTC.

        Our retail marketing strategy is focused on SSA’sSSA's Midwest operations, additional growth of the Marathon brand and continued growth for PTC.

14


Supply and Transportation

        We obtain most of the crude oil we processrefine from negotiated contracts and spot purchases or exchanges.exchanges on the spot market. In 2005, our net purchases of2006, U.S. producedsourced crude oil for refinery input averaged 447,000 bpd,470 mbpd, or 4648 percent of the crude oil processed at our refineries, including a net 12,000 bpd14 mbpd from our production operations. In 2005,2006, Canada was the source for 1113 percent, or 111,000 bpd,130 mbpd of crude oil processed and other foreign sources supplied 4339 percent, or 415,000 bpd,380 mbpd, of the crude oil processed by our refineries, including approximately 221,000 bpd198 mbpd from the Middle East. This crude oil was acquired from various foreign national oil companies, producing companies and trading companies.

The following table provides information on the sources of crude for each of the last three years.


Sources of Crude Oil Refined

(Thousands of Barrels per Day)

 2006
 2005
 2004

United States  470  447  416
Canada  130  111  130
Middle East and Africa  266  301  276
Other International  114  114  117
  
 
 
TOTAL  980  973  939

Average cost of crude oil throughput ($ per barrel)

 

$

61.15

 

$

51.85

 

$

39.16

        We operate a system of pipelines, terminals and terminalsbarges to provide crude oil to our refineries and refined products to our marketing areas. At December 31, 2005,2006, we owned, leased, operated or leased approximately 2,774held equity method investments in 68 miles of crude oil gathering lines, 3,718 miles of crude oil trunk lines and 3,8243,855 miles of refined product trunk lines.

        Excluding equity method investees, our owned or operated common carrier pipelines transported the volumes shown in the following table for each of the last three years.


Pipeline Barrels Handled

(In millions)

 2006
 2005
 2004

Crude oil gathering lines 6 7 7
Crude oil trunk lines 542 591 569
Refined products trunk lines 402 445 407
  
 
 
TOTAL 950 1,043 983

        At December 31, 20052006 we had interests in the following pipelines:

• 100 percent ownership of Ohio River Pipe Line LLC, which owns a refined products pipeline extending from Kenova, West Virginia to Columbus, Ohio, known as Cardinal Products Pipeline;
• 50 percent interest in Centennial Pipeline LLC, which owns a refined products system connecting Gulf Coast refineries with the Midwest market;
• 51 percent interest in LOOP LLC (“LOOP”), which is the owner and operator of the only U.S. deepwater oil port, located 18 miles off the coast of Louisiana;
• 59 percent interest in LOCAP LLC, which owns a crude oil pipeline connecting LOOP and the Capline system;
• 37 percent interest in the Capline system, a large diameter crude oil pipeline extending from St. James, Louisiana to Patoka, Illinois;
• 17 percent interest in Explorer Pipeline Company, which is a refined products pipeline system extending from the Gulf of Mexico to the Midwest;
• 33 percent interest in Minnesota Pipe Line Company, which owns a crude oil pipeline extending from Clearbrook, Minnesota to Cottage Grove, Minnesota, which is in the vicinity of MPC’s St. Paul Park, Minnesota refinery;
• 60 percent interest in Muskegon Pipeline LLC, which owns a refined products pipeline extending from Griffith, Indiana to North Muskegon, Michigan; and
• 6 percent interest in Wolverine Pipe Line Company, a refined products pipeline system extending from Chicago, Illinois to Toledo, Ohio.

15


        Our 8587 owned and operated light product and asphalt terminals are strategically located throughout the Midwest, upper Great Plains and Southeast. These facilities are supplied by a combination of pipelines, barges, rail cars and/orand trucks. Our marine transportation operations include towboats (15 owned) and barges (180 owned, 4 leased) that transport refined products on the Ohio, Mississippi and Illinois rivers, their tributaries and the Intercoastal Waterway. We also lease and own over 2,000 rail cars of various sizes and capacities for movement and storage of petroleum products and a large number ofover 100 tractors and tank trailers.

     Effective October 15,

Ethanol Production

        In 2006, mostwe signed a definitive agreement forming a 50/50 joint venture that will construct and operate one or more ethanol production plants. Our partner in the joint venture will provide the day-to-day management of the diesel fuel sold for highway use must contain no more than 15 partsplants, as well as grain procurement, distillers dried grain marketing and ethanol management services. This venture will enable us to maintain the reliability of a portion of our future ethanol supplies. Together with our partner, we selected the venture's initial plant site, Greenville, Ohio, and construction has commenced on a 110 million gallon per million of sulfur at the retail outlet. This new ultra low sulfur diesel (“ULSD”) fuel requirement will place a premium on ensuring that thereyear ethanol facility. The facility is no contamination of the ULSD while it is in transit to the retail outlet. We expectexpected to be able to meet these requirements.

operational as soon as the first quarter of 2008.

        The above discussion of the RM&T segment includes forward-looking statements concerning the possibleplanned expansion of the Garyville refinery.refinery, potential heavy oil refining upgrading projects and a joint venture that would construct and operate ethanol plants. Some factors that could affect the Garyville expansion project and the ethanol plant construction, management and development include the results of the FEED work, necessary regulatorygovernment and third party approvals, crude oil supply and transportation logistics, necessary permits and continued favorable investment climate, availability of materials and labor, unforeseen hazards such as weather conditions and other risks customarily associated with construction projects. The Garyville project may be further affected by crude oil supply. These factors (among others) could cause actual results to differ materially from those set forth in the forward-looking statements.

Factors that could affect the heavy oil refining upgrading projects include unforeseen difficulty in negotiation of definitive agreements, results of front-end engineering and design work, approval of our Board of Directors, inability or delay in obtaining necessary government and third-party approvals, continued favorable investment climate, and other geological, operating and economic considerations.

15Other


        The Energy Policy Act of 2005 established a Renewable Fuel Standard ("RFS") providing that all gasoline sold in the United States contain a minimum of 4.0 billion gallons of renewable fuel in 2006. The RFS increases gradually each year until 2012, when the RFS will be 7.5 billion gallons of renewable fuel. The U.S. Environmental Protection Agency ("EPA") has published a proposed rule to implement the RFS, and we anticipate that a final rule will be published in mid-2007. Federal legislation may be proposed in 2007 which may require even greater quantities of renewable fuels. Marathon intends to comply with all regulations that are adopted.


Integrated Gas

        Our integrated gas operations include natural gas liquefaction and regasification operations, methanol operations, and certain other gas processing facilities and pipeline operations, and marketing and transportation of natural gas.facilities. Also included in the financial results of the Integrated Gas segment are the costs associated with ongoing development of certain integratedprojects to link stranded natural gas projects.

resources with key demand areas.

16



Alaska LNG

        We own a 30 percent interest in a Kenai, Alaska, natural gas liquefaction plant and two 87,500 cubic meter tankers used to transport LNG to customers in Japan. Feedstock for the plant is supplied from a portion of our natural gas production in the Cook Inlet. From the first production in 1969, the LNG has been sold under a long-term contract with two of Japan’sJapan's largest utility companies. This contract continues through March 2009, with 20052006 LNG deliveries totaling 6561 gross bcf (22(19 net bcf).

In January 2007, along with our partner, we filed a request with the U.S. Department of Energy to extend the export license for this natural gas liquefaction plant through March 2011.

Equatorial Guinea LNG Project

        In 2004, we and our partner, Compania Nacional de Petroleos de Guinea Ecuatorial (“GEPetrol”), the(the National Oil Company of Equatorial Guinea or "GEPetrol"), through Equatorial Guinea LNG Holdings Limited (“EGHoldings”("EGHoldings"), began construction of ana 3.7 million metric ton per annum ("mmtpa") LNG plantproduction facility on Bioko Island that will initially deliver a contracted offtakeIsland. We expect to begin delivering 3.4 mmtpa, or 460 mmcfd, during the second quarter of 3.4 million metric tons per year beginning in 2007 (approximately 460 mmcfd) under a Sales17-year sales and Purchase Agreement with a subsidiarypurchase agreement. The purchaser under this agreement will take delivery of BG Group plc (“BGML”). BGML will purchase the LNG plant’sfacility's production for a period of 17 years on an FOB Bioko Island basis with pricing linked principally to the Henry Hub index. The LNG plant is ultimately expected to have the ability to operate at higher rates and for a longer period than the current contracted offtake rate and term.index, regardless of destination. This project will allow us to monetize our natural gas reserves from the Alba field, as natural gas for the plantproduction facility will be purchased from the Alba field participants under a long-term natural gas supply agreement. ConstructionWe are currently seeking additional natural gas supplies to allow full utilization of this LNG facility, which is designed to have a higher capacity and a longer life than the plant is ahead of schedule with first shipment of LNG expected in the third quarter of 2007.

     Oncurrent 17-year sales and purchase agreement.

        In July 25, 2005, Marathon and GEPetrol entered into agreements under which Mitsui & Co., Ltd. (“Mitsui”("Mitsui") and a subsidiary of Marubeni Corporation (“Marubeni”("Marubeni") acquired 8.5 percent and 6.5 percent interests respectively, in EGHoldings. In November 2006, GEPetrol transferred its 25 percent interest to Sociedad Nacional de Gas de Guinea Ecuatorial ("SONAGAS"), which is also controlled by the government of Equatorial Guinea. Following thethese transaction, we hold a 60 percent interest in EGHoldings, with GEPetrolSONAGAS holding a 25 percent interest and Mitsui and Marubeni holding the remaining interests.

     The EGHoldings

        In 2006, with our project partners, are also exploring the feasibility of addingwe awarded a FEED contract for initial work related to a potential second LNG trainproduction facility on Bioko Island, Equatorial Guinea. The FEED work is expected to be completed during 2007. The scope of the FEED work for the potential 4.4 mmtpa LNG project includes feed gas metering, liquefaction, refrigeration, ethylene storage, boil off gas compression, product transfer to storage and LNG product metering. A final investment decision is expected in an effort to create a regional gas hub that would commercialize stranded natural gas from various sources in the surrounding Gulf of Guinea region.

early 2008.

Elba Island LNG

        In April 2004, we began delivering LNG cargoes as part of ourat the Elba Island, Georgia LNG regasification terminal capacity rightspursuant to an LNG sales and purchase agreement. Under the terms of the agreement, we can supplyhave the right to deliver and sell up to 58 billion cubic feetbcf of natural gas (as LNG) per year, into the terminal through March 31, 2021 with a possible extension to November 30, 2023.

        In September 2004, we signed an agreement with BP Energy Company (“BP”) under which BPwe will supply usbe supplied with 58 bcf of natural gas per year, as LNG, for a minimum period of five years. The agreement allows for delivery of LNG at the Elba Island LNG regasification terminal with pricing linked to the Henry Hub index. This supply agreement with BP enables us to fully utilize our capacity rights at Elba Island during the period of this agreement, while affording us the flexibility to access this capacity to commercialize other stranded natural gas resources beyond the term of the BPthis contract. The agreement commenced in 2005.

Methanol

        We own a 45 percent interest in Atlantic Methanol Production Company LLC (“AMPCO”),AMPCO, which owns a methanol plant located in Malabo, Equatorial Guinea. Feedstock for the plant is supplied from a portion of our natural gas production in the Alba field. Methanol sales totaled 1,052,000733,680 gross metric tons (473,000(330,156 net metric tons) in 2005.2006. Production from the plant is used to supply customers in Europe and the U.S.

     AMPCO will undergo a scheduled maintenance shutdown during the second quarter of 2006. During the outage, AMPCO will also seek to remove bottlenecks in several parts of the plant.
Natural Gas Marketing and Transportation Activities
     In addition to the sale of our own natural gas production, we purchase gas from third-party producers and marketers for resale.
United States.

16


     During 2005, we sold our 24 percent interest in Nautilus Pipeline Company, LLC and our 24 percent interest in Manta Ray Offshore Gathering Company, LLC, which are both Gulf of Mexico natural gas pipeline systems. We still own a 34 percent interest in the Neptune natural gas processing plant located in St. Mary Parish, Louisiana. The plant has the capacity to process 600 mmcfd of natural gas, which is supplied by the Nautilus pipeline system.
Gas Technology

        We invest in natural gas technology research, includinggas-to-liquids (“GTL” gas-to-liquids ("GTL") technology which was successfully applied in a GTL demonstration plant atoffers the Port of Catoosa, Oklahoma in 2004.ability to convert natural gas into premium fuels. In addition to GTL, we are continuingcontinue to exploreevaluate application of gas technologies accessible through licenses, including methanol to power, gas to fuelsmethanol-to-power and compressed natural gas. We also continue to develop a

17



proprietary gas-to-fuels ("GTF") technology, which can be configured to convert natural gas technologies.

resources into premium fuels.

        The above discussion of the integrated gas segment contains forward looking statements with respect to the timing and levels of production associated with the LNG plantproduction facility and the possible expansion thereof. Factors that could affect the LNG plantproduction facility include unforeseen problems arising from construction, inability or delay in obtaining necessary government and third-party approvals, unanticipated changes in market demand or supply, environmental issues, availability or constructioncommissioning of sufficient LNG vessels, andthe facilities, unforeseen hazards such as weather conditions.conditions and other operating considerations such as shipping the LNG. In addition to these factors, other factors that could potentially affect the possible expansion of the current LNG projectproduction facility and the development of additional LNG capacity through additional projects include partner approvals, access to sufficient natural gas volumes through exploration or commercial negotiations with other resource owners and access to sufficient regasification capacity. The foregoing factors (among others) could cause actual results to differ materially from those set forth in the forward-looking statements.


Competition and Market Conditions

        Strong competition exists in all sectors of the oil and gas industry and, in particular, in the exploration and development of new reserves. We compete with major integrated and independent oil and gas companies, as well as national oil companies, for the acquisition of oil and natural gas leases and other properties. We compete with these companies, as well as national oil companies for the equipment and labor required to develop and operate those properties and in the marketing of oil and natural gas to end-users. Many of our competitors have financial and other resources greater than those available to us. As a consequence, we may be at a competitive disadvantage in bidding for the rights to explore for oil and natural gas. Acquiring the more attractive exploration opportunities frequently requires competitive bids involving front-end bonus payments orcommitments-to-work commitments-to-work programs. We also compete in attracting and retaining personnel, including geologists, geophysicists and other specialists. Based on industry sources, we believe we currently rank ninth amongU.S.-based petroleum companies on the basis of 2005 worldwide liquid hydrocarbon and natural gas production.

        We must also compete with a large number of other companies to acquire crude oil for refinery processing and in the distribution and marketing of a full array of petroleum products. We rank fifth among U.S. petroleum companies on the basis of U.S. crude oil refining capacity as of December 31, 2005.2006. We compete in four distinct markets – wholesale, spot, branded and retail distribution – for the sale of refined products. We believe we compete with about 3040 companies in the wholesale distribution of petroleum products to private brand marketers and large commercial and industrial consumers; about 7570 companies in the sale of petroleum products in the spot market; nine refiner/marketers in the supply of branded petroleum products to dealers and jobbers; and approximately 220260 petroleum product retailers in the retail sale of petroleum products. We compete in the convenience store industry through SSA’sSSA's retail outlets. The retail outlets offer consumers gasoline, diesel fuel (at selected locations) and a broad mix of other merchandise and services. Some locations also have on-premises brand-name restaurants such as SubwaytmSubway™. We also compete in the travel center industry through our 50 percent ownership in PTC.

        Our operating results are affected by price changes in crude oil, natural gas and petroleum products, as well as changes in competitive conditions in the markets we serve. Generally, results from production operations benefit from higher crude oil and natural gas prices while the refining and wholesale marketing marginsgross margin may be adversely affected by crude oil price increases. Price differentials between sweet and sour crude oil also affect operating results. Market conditions in the oil and gas industry are cyclical and subject to global economic and political events and new and changing governmental regulations.


The Separation

        On December 31, 2001, pursuant to an Agreement and Plan of Reorganization dated as of July 31, 2001, Marathon completed the Separation, in which:

• its wholly-owned subsidiary United States Steel LLC converted into a Delaware corporation named United States Steel Corporation and became a separate, publicly traded company; and
• USX Corporation changed its name to Marathon Oil Corporation.

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        As a result of the Separation, Marathon and United States Steel are separate companies and neither has any ownership interest in the other. Effective January 31, 2006, Thomas J. Usher retired as chairman of the board of directors and as a director of United States Steel, and Dr. Shirley Ann Jackson retired as a director of United States Steel. As a result, three remaining members of our board of directors are also directors of United States Steel.

        In connection with the Separation and pursuant to the Plan of Reorganization, Marathon and United States Steel have entered into a series of agreements governing their relationship after the Separation and providing for the allocation of tax and certain other liabilities and obligations arising from periods before the Separation. The following is a description of the material terms of two of those agreements.

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Financial Matters Agreement

        Under the financial matters agreement, United States Steel has assumed and agreed to discharge all Marathon’sof Marathon's principal repayment, interest payment and other obligations under the following, including any amounts due on any default or acceleration of any of those obligations, other than any default caused by Marathon:

• obligations under industrial revenue bonds related to environmental projects for current and former U.S. Steel Group facilities, with maturities ranging from 2009 through 2033;
• sale-leaseback financing obligations under a lease for equipment at United States Steel’s Fairfield Works facility, with the lease term extending to 2012, subject to extensions;
• obligations relating to various lease arrangements accounted for as operating leases and various guarantee arrangements, all of which were assumed by United States Steel; and
• certain other guarantees.

        The financial matters agreement also provides that, on or before the tenth anniversary of the Separation, United States Steel will provide for Marathon’sMarathon's discharge from any remaining liability under any of the assumed industrial revenue bonds. United States Steel may accomplish that discharge by refinancing or, to the extent not refinanced, paying Marathon an amount equal to the remaining principal amount of all accrued and unpaid debt service outstanding on, and any premium required to immediately retire, the then outstanding industrial revenue bonds.

        Under the financial matters agreement, United States Steel shall have the right to exercisehas all of the existing contractual rights under the lease obligationsleases assumed from Marathon, including all rights related to purchase options, prepayments or the grant or release of security interests. However, United States Steel shall havehas no right to increase amounts due under or lengthen the term of any of the assumed lease obligations without the prior consent of Marathon other than extensions set forth in the terms of the assumed lease obligations.

leases, other than extensions set forth in the terms of any of the assumed leases.

        The financial matters agreement also requires United States Steel to use commercially reasonable efforts to have Marathon released from its obligations under a guarantee Marathon provided with respect to all of United States Steel’sSteel's obligations under a partnership agreement between United States Steel, as general partner, and General Electric Credit Corporation of Delaware and Southern Energy Clairton, LLC, as limited partners. United States Steel may dissolve the partnership under certain circumstances, including if it is required to fund accumulated cash shortfalls of the partnership in excess of $150 million. In addition to the normal commitments of a general partner, United States Steel has indemnified the limited partners for certain income tax exposures.

        The financial matters agreement requires Marathon to use commercially reasonable efforts to take all necessary action or refrain from acting so as to assure compliance with all covenants and other obligations under the documents relating to the assumed obligations to avoid the occurrence of a default or the acceleration of the payment obligations underpayments on the assumed obligations. The agreement also obligates Marathon to use commercially reasonable efforts to obtain and maintain letters of credit and other liquidity arrangements required under the assumed obligations.

        United States Steel’sSteel's obligations to Marathon under the financial matters agreement are general unsecured obligations that rank equal to United States Steel’sSteel's accounts payable and other general unsecured obligations. The financial matters agreement does not contain any financial covenants and United States Steel is free to incur additional debt, grant mortgages on or security interests in its property and sell or transfer assets without our consent.

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Tax Sharing Agreement

        Marathon and United States Steel have a tax sharing agreement that applies to each of their consolidated tax reporting groups. Provisions of this agreement include the following:

• for any taxable period, or any portion of any taxable period, ended on or before December 31, 2001, unpaid tax sharing payments will be made between Marathon and United States Steel generally in accordance with the general tax sharing principles in effect before the Separation;
• no tax sharing payments will be made with respect to taxable periods, or portions thereof, beginning after December 31, 2001; and
• provisions relating to the tax and related liabilities, if any, that result from the Separation ceasing to qualify as a tax-free transaction and limitations on post-Separation activities that might jeopardize the tax-free status of the Separation.
     Under the general tax sharing principles in effect before the Separation:
• the taxes payable by each of the Marathon Group and the U.S. Steel Group were determined as if each of them had filed its own consolidated, combined or unitary tax return; and
• the U.S. Steel Group would receive the benefit, in the form of tax sharing payments by the parent corporation, of the tax attributes, consisting principally of net operating losses and various credits, that its business generated and the parent used on a consolidated basis to reduce its taxes otherwise payable.
     In accordance with the tax sharing agreement, at the time of the Separation, Marathon made a preliminary settlement with United States Steel of approximately $440 million as the net tax sharing payments owed to it for the year ended December 31, 2001 under the pre-Separation tax sharing principles.
     The tax sharing agreement also addresses the handling of tax audits and contests and other matters respecting taxable periods, or portions of taxable periods, ended before December 31, 2001.
     In the tax sharing agreement, each of Marathon and United States Steel promised the other party that it:
• would not, before January 1, 2004, take various actions or enter into various transactions that might, under section 355 of the Internal Revenue Code of 1986, jeopardize the tax-free status of the Separation; and
• would be responsible for, and indemnify and hold the other party harmless from and against, any tax and related liability, such as interest and penalties, that results from the Separation ceasing to qualify as tax-free because of its taking of any such action or entering into any such transaction.
     The prescribed actions and transactions include:
• the liquidation of Marathon or United States Steel; and
• the sale by Marathon or United States Steel of its assets, except in the ordinary course of business.
     In case a taxing authority seeks to collect a tax liability from one party that the tax sharing agreement has allocated to the other party, the other party has agreed in the sharing agreement to indemnify the first party against that liability.
     Even if the Separation otherwise qualified for tax-free treatment under section 355 ofDuring 2006, the Internal Revenue Code, the Separation may become taxable to Marathon under section 355(e) of the Internal Revenue Code if capital stock representing a 50 percent or greater interest in either Marathon or United States Steel is acquired, directly or indirectly, as part of a plan or series of related transactions that include the Separation. For this purpose, a “50 percent or greater interest” means capital stock possessing at least 50 percent of the total combined voting powerService completed its review of all classes of stock entitled to vote or at least 50 percent of the total value of shares of all classes of capital stock. To minimize this risk, both Marathon and United States Steel agreed in thefederal income tax sharing agreement that they would not enter into any transactions or make any change in their equity structures that could cause the Separation to be treated as part of a plan or series of related transactions to which those provisions of section 355(e) of the Internal Revenue Code may apply. If an acquisition occurs that results in the Separation being taxable under section 355(e) of the Internal Revenue Code, the agreement provides that the resulting corporate tax liability will be bornereturns filed by the party involved in that acquisition transaction.
     Although the tax sharing agreement allocates tax liabilities relating toUSX Corporation for taxable periods ending on or prior to the Separation, eachdate of the Separation. Marathon and United States Steel as members of the same consolidated tax reporting group during any portion of a taxable period ended on or priorhave settled all matters related to the date of the Separation, is jointly and severally liable under the Internal Revenue Code for the federal income tax liability of the entire consolidated tax reporting group for that year. To address the possibility that the taxing authorities may seektaxes under this agreement. Remaining matters related to collect all or part of a tax liability from one party where the tax sharing agreement allocates that liabilitystate and local income taxes are not expected to the other party, the agreement includes
have any significant effect on Marathon.

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indemnification provisions that would entitle the party from whom the taxing authorities are seeking collection to obtain indemnification from the other party, to the extent the agreement allocates that liability to that other party. Marathon can provide no assurance, however, that United States Steel will be able to meet its indemnification obligations, if any, to Marathon that may arise under the tax sharing agreement.
Obligations Associated with the Separation as of December 31, 20052006

        See “Management’s"Management's Discussion and Analysis of Financial Condition and Results of Operations – Obligations Associated with the Separation of United States Steel”Steel" for a discussion of Marathon’sour obligations associated with the Separation.

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Environmental Matters

      We maintain a comprehensive environmental policy overseen by the

        The Corporate Governance and Nominating Committee of our Board of Directors.Directors is responsible for overseeing our position on public issues identified by management, including environmental matters. Our Corporate Responsibility organization has the responsibility to ensure that our operating organizations maintain environmental compliance systems that are in accordance with applicable laws and regulations. The Corporate Responsibility Management Committee, which isCommittees comprised of certain of our officers is charged with reviewingreview our overall performance with various environmental compliance programs. We also have a Crisis Management Team, composed primarily of senior management, which oversees the response to any major emergency, environmental or other incident involving Marathon or any of our properties.

        Legislation and regulations pertaining to climate change and greenhouse gas emissions have the potential to impact us. The Kyoto Protocol, effective in 2005, has been ratified by countries in which we have or in the future may have operations. Other climate change legislation and regulations both in the United States and abroad are in various stages of development. Although there may be financial impact (including compliance costs) associated with any legislation or regulation, the extent and magnitude of impact cannot be reliably or accurately estimated due to the present uncertainty of these measures. As part of our commitment to environmental stewardship, we estimate and publicly report greenhouse gas emissions from our operations. We are working to continuously improve the accuracy and completeness of these estimates. In addition, we continuously strive to improve operational and energy efficiencies through resource and energy conservation where practicable and cost effective.

        Our businesses are subject to numerous laws and regulations relating to the protection of the environment. These environmental laws and regulations include the Clean Air Act (“CAA”("CAA") with respect to air emissions, the Clean Water Act (“CWA”("CWA") with respect to water discharges, the Resource Conservation and Recovery Act (“RCRA”("RCRA") with respect to solid and hazardous waste treatment, storage and disposal, the Comprehensive Environmental Response, Compensation, and Liability Act (“CERCLA”("CERCLA") with respect to releases and remediation of hazardous substances and the Oil Pollution Act of 1990(“OPA-90” ("OPA-90") with respect to oil pollution and response. In addition, many states where we operate have similar laws dealing with the same matters. New laws are being enacted and regulations are being adopted by various regulatory agencies on a continuing basis, and the costs of compliance with these new rules can only be broadly appraised until their implementation becomes more accurately defined. In some cases, they can impose liability for the entire cost of cleanup on any responsible party without regard to negligence or fault and impose liability on us for the conduct of others or conditions others have caused, or for our acts that complied with all applicable requirements when we performed them. The ultimate impact of complying with existing laws and regulations is not always clearly known or determinable because certain implementing regulations for some environmental laws have not yet been finalized or, in some instances, are undergoing revision. These environmental laws and regulations, particularly the 1990 Amendments to the CAA and its implementing regulations, new water quality standards and stricter fuel regulations, could result in increased capital, operating and compliance costs.

        For a discussion of environmental capital expenditures and costs of compliance for air, water, solid waste and remediation, see “Management’s"Management's Discussion and Analysis of Environmental Matters, Litigation and Contingencies”Contingencies" and “Legal"Legal Proceedings.

"

Air

        Of particular significance to our refining operations arewere U.S. Environmental Protection Agency (“EPA”)EPA regulations that requirerequired reduced sulfur levels starting in 2004 for gasoline and 2006 for diesel fuel. Our combined capital costs to achieveWe achieved compliance with these rules are expectedregulations and began production of ultra-low sulfur diesel fuel for on-road use prior to approximate $900the June 1, 2006 deadline. The cost of achieving compliance with these regulations was approximately $850 million. Marathon will also be spending approximately $250 million from 2006 through 2010 to produce ultra-low sulfur diesel fuel for off-road use. Further, Marathon estimates that it will spend approximately $400 million over thea four-year period between 2002 and 2006, which includes costs that could be incurred as part of other refinery upgrade projects. Costs incurred through December 31, 2005 were approximately $825 million,beginning in 2008 to comply with the remainder expectedMobile Source Air Toxics II regulations relating to be incurred in 2006.benzene. This is a forward-looking statement. Some factors (among others) that could potentially affect gasoline and diesel fuel compliance costs include completionpreliminary estimate as the Mobile Source Air Toxics II regulations should be finalized in the first half of construction andstart-up activities.

2007.

        The EPA has finalized new and revised National Ambient Air Quality Standards (“NAAQS”("NAAQS") for fine particulate emissions (PM2.5) and ozone. In connection with these new standards, the EPA will designate certain areas as “nonattainment,”"nonattainment," meaning that the air quality in such areas does not meet the NAAQS. To address these nonattainment areas, in January 2004, the EPA proposed a rule called the Interstate Air Quality Rule (“IAQR”("IAQR") that would require significant reductions of SO2SO2 and NOx emissions in numerous states. The final rule was promulgated on May 12, 2005, and the rule was renamed the Clean Air Interstate Rule (“CAIR”("CAIR"). While the EPA expects that states will meet their CAIR obligations by requiring emissions reductions from Electric Generating Units (“EGUs”("EGUs"), states will have the final say on what sources they regulate to meet attainment criteria. Our refinery operations are located in affected states and some states may choose to propose more stringent fuels requirements to meet the CAIR

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requirements; however we cannot reasonably estimate the final financial impact of the state actions to implement the CAIR until the states have taken further action.

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Water

        We maintain numerous discharge permits as required under the National Pollutant Discharge Elimination System program of the CWA and have implemented systems to oversee our compliance efforts. In addition, we are regulated under OPA-90, which amended the CWA. Among other requirements, OPA-90 requires the owner or operator of a tank vessel or a facility to maintain an emergency plan to respond to releases of oil or hazardous substances. Also, in case of such releases OPA-90 requires responsible companies to pay resulting removal costs and damages, provides for civil penalties and imposes criminal sanctions for violations of its provisions.

        Additionally, OPA-90 requires that new tank vessels entering or operating in U.S. waters be double hulled and that existing tank vessels that are not double-hulled be retrofitted or removed from U.S. service, according to a phase-out schedule. As of December 31, 2005, allAll of the barges used for river transport of our feedstocksraw materials and refined products meet the double-hulled requirements of OPA-90.

We operate facilities at which spills of oil and hazardous substances could occur. Several coastal states in which we operate have passed state laws similar to OPA-90, but with expanded liability provisions, including provisions for cargo owner responsibility as well as ship owner and operator responsibility. We have implemented emergency oil response plans for all of our components and facilities covered by OPA-90.

Solid Waste

        We continue to seek methods to minimize the generation of hazardous wastes in our operations. RCRA establishes standards for the management of solid and hazardous wastes. Besides affecting waste disposal practices, RCRA also addresses the environmental effects of certain past waste disposal operations, the recycling of wastes and the regulation of underground storage tanks (“USTs”("USTs") containing regulated substances. We have ongoing RCRA treatment and disposal operations at someone of our RM&T facilities and primarily utilize offsite third-party treatment and disposal facilities. Ongoing RCRA-related costs are not expected to be material.

Remediation

        We own or operate certain retail outlets where, during the normal course of operations, releases of petroleum products from USTs have occurred. Federal and state laws require that contamination caused by such releases at these sites be assessed and remediated to meet applicable standards. The enforcement of the UST regulations under RCRA has been delegated to the states, which administer their own UST programs. Our obligation to remediate such contamination varies, depending on the extent of the releases and the stringency of the laws and regulations of the states in which we operate. A portion of these remediation costs may be recoverable from the appropriate state UST reimbursement funds once the applicable deductibles have been satisfied. AccrualsWe also have other facilities which are subject to remediation under federal or state law. See Legal Proceedings – Environmental Proceedings – Other Proceedings for remediation expenses and associated reimbursements are established for sites where contamination has been determined to exist and the amounta discussion of associated costs is reasonably determinable.

these sites.


Employees

        We had 27,75628,195 active employees as of December 31, 2005.2006. Of that number, 18,25719,132 were employees of Speedway SuperAmerica LLC,SSA, most of whichwhom were employed at our retail marketing outlets.

        Certain hourly employees at our Catlettsburg and Canton refineries are represented by the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers Union under labor agreements that expire on January 31, 2009. The same union represents certain hourly employees at our Texas City refinery under a labor agreement that expires on March 31, 2009. The International Brotherhood of Teamsters represents certain hourly employees under labor agreements that are scheduled to expire on May 31, 20062009 at our St. Paul Park refinery and January 31, 20072010 at our Detroit refinery.


Available Information

        General information about Marathon, including the Corporate Governance Principles and Charters for the Audit Committee, Compensation Committee, Corporate Governance and Nominating Committee and Committee on Financial Policy, can be found at www.marathon.com. In addition, our Code of Business Conduct and Code of Ethics for Senior Financial Officers are available on the website at www.marathon.com/Our Values/CorporateGovernance/. Marathon’sMarathon's Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, as well as any amendments and exhibits to those reports, are available free of charge through the website as soon as reasonably practicable after the reports are filed or furnished with the SEC. These documents are also available in hard copy, free of charge, by contacting our Investor Relations office. Information contained on our website is not incorporated into this Annual Report on Form 10-K or other securities filings.

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Item 1A. Risk Factors

        Marathon is subject to various risks and uncertainties in the course of its business. The following summarizes some, but not all, of the risks and uncertainties that may adversely affect our business, financial condition or results of operations.

A substantial or extended decline in oil or natural gas prices, as well as refined product gross margins, would reduce our revenues, operating results and cash flows and could adversely impact our future rate of growth.

growth and the carrying value of our assets.

        Prices for oil and natural gas and refined product gross margins fluctuate widely. Our revenues, operating results and future rate of growth are highly dependent on the prices we receive for our oil, natural gas and refined products. Historically, the markets for oil, natural gas and refined products have been volatile and may continue to be volatile in the future. Many of the factors influencing prices of oil, natural gas and refined products are beyond our control. These factors include:

• worldwide and domestic supplies of and demand for oil and natural gas;
• the ability of the members of the Organization of Petroleum Exporting Countries to agree to and maintain oil price and production controls;
• political instability or armed conflict in oil-producing regions; and
• domestic and foreign governmental regulations and taxes.

        The long-term effects of these and other conditionsfactors on the prices of oil and natural gas, as well as on refined product gross margins, are uncertain.

        Lower oil and natural gas prices, as well as lower refined product gross margins, may reduce the amount of oil and natural gasthese commodities that we produce, which may reduce our revenues, operating income and operating income.cash flows. Significant reductions in oil and natural gas prices or refined product gross margins could require us to reduce our capital expenditures.

expenditures and impair the carrying value of our assets.

Estimates of oil and natural gas reserves depend on many factors and assumptions, including various assumptions that are based on conditions in existence as of the dates of the estimates. Any material changes in those conditions or other factors affecting those assumptions could impair the quantity and value of our oil and natural gas reserves.

        The proved oil and natural gas reservereserves information related to Marathon included in this Reportreport has been derived from engineering estimates. Those estimates were prepared by our personnelin-house teams of reservoir engineers and geoscience professionals and reviewed, on a selected basis, by our Corporate Reserves Group and/or third-party petroleum engineers.consultants we have retained. The estimates were calculated using oil and natural gas prices in effect as of December 31, 2005,2006, as well as other conditions in existence as of that date. Any significant future price changes maywill have a material effect on the quantity and present value of our proved reserves. Future reserve revisions could also result from changes in, among other things, governmental regulation and severance and other production taxes.

        Reserve estimation is a subjective process that involves estimating volumes to be recovered from underground accumulations of oil and natural gas that cannot be directly measured. Estimates of economically recoverable oil and natural gas reserves and of future net cash flows depend upon a number of variable factors and assumptions, including:

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        As a result, different petroleum engineers, each using industry-accepted geologic and engineering practices and scientific methods, may produce different estimates of reserves and future net cash flows based on the same available data. Because of the subjective nature of oil and natural gas reserve estimates, each of the following items may differ materially from the amounts or other factors estimated:

• the amount and timing of oil and natural gas production;
• the revenues and costs associated with that production; and
• the amount and timing of future development expenditures.


        The discounted future net revenues from our proved reserves includedreflected in this Reportreport should not be considered as the market value of the reserves attributable to our properties. As required by generally accepted accounting principles,SEC Rule 4-10 of Regulation S-X, the estimated discounted future net revenues from our proved reserves are based generally on prices and costs as of the date of the estimate, while actual future prices and costs may be materially higher or lower.

        In addition, the 10 percent discount factor that is required by the applicable rules of the SEC to be used to calculate discounted future net revenues for reporting purposes under generally accepted accounting principles is not necessarily the most appropriate discount factor based on theour cost of capital in effect from time to time and the risks associated with our business and the oil and natural gas industry in general.

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If we are unsuccessful in acquiring or finding additional reserves, our future oil and natural gas production would decline, thereby reducing our cash flows and results of operations and impairing our financial condition.

        The rate of production from oil and natural gas properties generally declines as reserves are depleted. Except to the extent we acquire interests in additional properties containing proved reserves, conduct successful exploration and development activities or, through engineering studies, optimize production performance, identify additional behind-pipe zonesreservoirs not currently producing or secondary recovery reserves, our proved reserves will decline materially as oil and natural gas is produced.

Accordingly, to the extent we are not successful in replacing the oil and natural gas we produce, our future revenues will decline. Creating and maintaining an inventory of prospects for future production depends on many factors, including:

    obtaining rights to explore for, develop and produce oil and natural gas in promising areas;

    drilling success;

    the ability to complete long lead-time, capital-intensive projects timely and on budget; and

    the ability to find or acquire additional proved reserves at acceptable costs.

Increases in crude oil prices and environmental regulations may reduce our refined product gross margins.

        The profitability of our refining, marketing and transportation operations depends largely on the margin between the cost of crude oil and other feedstocks that we refine and the selling prices we obtain for refined products. We are a net purchaser of crude oil. A significant portion of our crude oil is purchased from various foreign national oil companies, producing companies and trading companies, including suppliers from the Middle East. These purchases are subject to political, geographic and economic risks attendant to doing business with suppliers located in that area of the world. Our overall RM&T profitability could be adversely affected by the availability of supply and rising crude oil and other feedstock prices which we do not recover in the marketplace. Refined product gross margins historically have been historically volatile and vary with the level of economic activity in the various marketing areas, the regulatory climate, logistical capabilities and the available supply of refined products.

        In addition, environmental regulations, particularly the 1990 amendments to the Clean Air Act, have imposed, and are expected to continue to impose, increasingly stringent and costly requirements on our refining, marketing and marketingtransportation operations, which may reduce our refined product gross margins.

If we do not compete successfully with our competitors, our future operating performance and profitability could materially decline.

        We compete with major integrated and independent oil and natural gas companies, as well as national oil companies, for the acquisition of oil and natural gas leases and other properties. We compete with these companies, as well as national oil companies for the equipment and labor required to develop and operate those properties and in the marketing of oil and natural gas to end-users. In addition, in implementing our integrated gas strategy, we compete with major integrated energy companies in

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bidding for and developing liquefied natural gas projects, which are very capital intensive. Many of our competitors have financial and other resources substantially greater than those available to us. As a consequence, we may be at a competitive disadvantage in acquiring additional properties and bidding for and developing additional projects, such as LNG plants.production facilities. Many of our larger competitors in the LNG market can complete more projects than we have the capacity to complete, which could lead those competitors to realize economies of scale that we are unable to realize. In addition, many of our larger competitors may be better able to respond to factors that affect the demand for oil and natural gas, such as changes in worldwide prices and levels of production, the cost and availability of alternative fuels and the application of government regulations.

We will continue to incur substantial capital expenditures and operating costs as a result of compliance with, and changes in environmental laws and regulations, and, as a result, our profitability could be materially reduced.

        Our businesses are subject to numerous laws and regulations relating to the protection of the environment. We have incurred and will continue to incur substantial capital, operating and maintenance, and remediation expenditures as a result of these laws and regulations. To the extent these expenditures, as with all costs, are not ultimately reflected in the prices of our products and services, our operating results will be adversely affected. The specific impact of these laws and regulations on each ofus and our competitors may vary depending on a number of factors, including the age and location of their operating facilities, marketing areaareas and production processes. We may also be required to make material expenditures to modify operations, install pollution control equipment, perform site cleanups or curtail operations. We may become subject to liabilities that we currently do not anticipate in connection with new, amended or more stringent requirements, stricter interpretations of existing requirements or the future discovery of contamination. In addition, any failure by us to comply with existing or future laws could result in civil or criminal fines and other enforcement actionactions against us.

        Our operations and those of our predecessors could expose us to civil claims by third parties for alleged liability resulting from contamination of the environment or personal injuries caused by releases of hazardous substances.

        Environmental laws are subject to frequent change and many of them have become more stringent. In some cases, they can impose liability for the entire cost of cleanup on any responsible party, without regard to negligence or fault, and impose liability on us for the conduct of others or conditions others have caused, or for our acts that complied with all applicable requirements when we performed them.

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Worldwide political and economic developments could damage our operations and materially reduce our profitability.
profitability and cash flows.

        Local political and economic factors in international markets could have a material adverse effect on us. Approximately 5056 percent of our oil and natural gas production in 20052006 was derived from production outside the United States and approximately 7072 percent of our proved reserves as of December 31, 20052006, were located outside the United States. In addition, we are increasing the focus of our development operations on areas outside the United States.

        There are many risks associated with operations in international markets, including changes in foreign governmental policies relating to crude oil, natural gas or refined product pricing and taxation, other political, economic or diplomatic developments and international monetary fluctuations. These risks include:

• political and economic instability, war, acts of terrorism and civil disturbances;
• the possibility that a foreign government may seize our property with or without compensation or may attempt to renegotiate or revoke existing contractual arrangements; and
• fluctuating currency values, hard currency shortages and currency controls.

        Continued hostilities in the Middle East and the occurrence or threat of future terrorist attacks could cause a downturn inadversely affect the economies of the United States and other developed countries. A lower level of economic activity could result in a decline in energy consumption, which could cause our revenues and margins to decline and limit our future growth prospects. More specifically, theseThese risks could lead to increased volatility in prices for crude oil, natural gas and refined products. In addition, these risks could increase instability in the financial and insurance markets and make it more difficult for us to access capital and to obtain the insurance coveragescoverage that we consider adequate.

        Actions of the United StatesU.S. government through tax and other legislation, executive order and commercial restrictions could reduce our operating profitability both in the United States and overseas.abroad. The United StatesU.S. government can prevent or restrict us from doing business in foreign countries. These restrictions and those of foreign governments have in the

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past limited our ability to operate in, or gain access to, opportunities in various countries. Actions by both the United States and host governments have affected operations significantly in the past and will continue to do so in the future.

Our operations are subject to business interruptions and casualty losses, and we do not insure against all potential losses and, therefore, we could be seriously harmed by unexpected liabilities.

        Our exploration and production operations are subject to unplanned occurrences, including blowouts, explosions, fires, loss of well control, spills, hurricanes and other adverse weather, labor disputes and maritime accidents. In addition, our refining, marketing and transportation operations are subject to business interruptions due to scheduled refinery turnarounds and unplanned events such as explosions, fires, pipeline ruptures or other interruptions, crude oil or refined product spills, inclement weather orand labor disputes. TheyOur operations are also subject to the additional hazards of pollution, releases of toxic gas and other environmental hazards and risks, as well as hazards of marine operations, such as capsizing, collision and damage or loss from severe weather conditions. These hazards could result in loss of human life, significant damage to property and equipment, environmental pollution, impairment of operations and substantial losses to us. Certain hazards have adversely affected us in the past, and litigation arising from a catastrophic occurrence in the future involving us or any of our assets or operations may result in our being named as a defendant in one or more lawsuits asserting potentially large claims or being assessed potentially substantial fines by governmental authorities.

        We maintain insurance against many, but not all, potential losses or liabilities arising from these operating hazards in amounts that we believe to be prudent. Uninsured losses and liabilities arising from operating hazards could reduce the funds available to us for exploration, drilling and production and could materially reduce our profitability.

Historically, we have maintained insurance coverage for physical damage and resulting business interruption to our major onshore and offshore facilities. Due to hurricane activity in recent years, the availability of insurance coverage for our offshore facilities for windstorms in the Gulf of Mexico region has been reduced or, in many instances, it is prohibitively expensive. As a result, our exposure to losses from future windstorm activity in the Gulf of Mexico region has increased.

If Ashland fails to pay its taxes, we could be responsible for satisfying various tax obligations of Ashland.

        As a result of the transactions in which we acquired the minority interest in MPC from Ashland in 2005, Marathon is severally liable for federal income taxes (and in some cases for certain state taxes) of Ashland for tax years of Ashland still open as of the date we completed the transactions. We have entered into a tax matters agreement with Ashland, which provides that:

• we will be responsible for the tax liabilities of the Marathon group of companies, including the tax liabilities of MPC and the other companies and businesses we acquired in the transactions (for periods after the completion of the transactions); and
• Ashland will generally be responsible for the tax liabilities of the Ashland group of companies before the completion of the transactions, and the income taxes attributable to Ashland’s interest in MPC before the completion of the transactions. However, under certain circumstances we will have several liability for those tax liabilities owed by Ashland to various taxing authorities, including the Internal Revenue Service.

If Ashland fails to pay any tax obligation for which we are severally liable, we may be required to satisfy this tax obligation. That would leave us in the position of having to seek indemnification from Ashland. In that event, our

24


indemnification claims against Ashland would constitute general unsecured claims, which would be effectively subordinate to the claims of secured creditors of Ashland, and we would be subject to collection risk associated with collecting unsecured debt from Ashland.

Marathon is required to pay Ashland for deductions relating to various contingent liabilities of Ashland, which could be material.

        We are required to claim tax deductions for certain contingent liabilities that will be paid by Ashland after completion of the transactions. Under the tax matters agreement, we are required to pay the benefit of those deductions to Ashland, with the computation and payment terms for such tax benefit payments divided into two “baskets,”"baskets," as described below:

Basket One –This applies to the first $30 million of contingent liability deductions (increased by inflation each year up to a maximum of $60 million) that we may claim in each year for the first 20 years following the acquisition. The benefit of Basket One deductions is determined by multiplying the amount of the deduction by 32% (or, if different, by a percentage equal to three percentage points less than the highest federal income tax rate during the applicable tax year). We are obligated to pay this amount to Ashland. The computation and payment of Basket One amounts does not depend on our ability to generate actual tax savings from the use of the contingent liability deductions in Basket One. Upon specified events related to Ashland (or after 20 years), the contingent liability deductions that would

25



otherwise have been compensated under Basket One will be taken into account in Basket Two. In addition, Basket One applies only for Federalfederal income tax purposes; state, local or foreign tax benefits attributable to specified liability deductions will be compensated only under Basket Two.

Because we are required to make payments to Ashland whether or not we generate any actual tax savings from the Basket One contingent liability deductions, the amount of our tax benefit payments to Ashland with respect to Basket One contingent liability deductions may exceed the aggregate tax benefits that we derive from these deductions. We are obligated to make these payments to Ashland even if we do not have sufficient taxable income to realize any benefit for the deductions.

Basket Two –All contingent liability deductions relating to Ashland’sAshland's pre-transactions operations that are not subject to Basket One are considered and compensated under Basket Two. The benefit of Basket Two deductions is determined on a “with"with and without”without" basis; that is, the contingent liability deductions are treated as the last deductions used by the Marathon group. Thus, if the Marathon group has deductions, tax credits or other tax benefits of its own, it will be deemed to use them to the maximum extent possible before it will be deemed to use the contingent liability deductions. To the extent that we have the capacity to use the contingent liability deductions based on this methodology, the actual amount of tax saved by the Marathon group through the use of the contingent liability deductions will be calculated and paid to Ashland. Because Basket Two amounts are calculated based on the actual tax saved by the Marathon group from the use of Basket Two deductions, those amounts are subject to recalculation in the event there is a change in the Marathon group’sgroup's tax liability for a particular year. This could occur because of audit adjustments or carrybacks of losses or credits from other years, for example. To the extent that such a recalculation results in a smaller Basket Two benefit with respect to a contingent liability deduction for which Ashland has already received compensation, Ashland is required to repay such compensation to Marathon. In the event we become entitled to any repayment, we would be subject to collection risks associated with collecting an unsecured claim from Ashland.

If the transactions resulting in our acquisition of the minority interest in MPC that was previously owned by Ashland were found to constitute a fraudulent transfer or conveyance, we could be required to provide additional consideration to Ashland or to return a portion of the interest in MPC, and either of those results could have a material adverse effect on us.

        In a bankruptcy case or lawsuit initiated by one or more creditors or a representative of creditors of Ashland, a court may review our recently completed2005 transactions with Ashland under the fraudulent transfer provisions of the U.S. Bankruptcy Code and comparable provisions of state fraudulent transfer or conveyance laws. Under those laws, the transactions would be deemed fraudulent if the court determined that the transactions were undertaken for the purpose of hindering, delaying or defrauding creditors or that the transactions were constructively fraudulent. If the transactions were found to be a fraudulent transfer or conveyance, we might be required to provide additional consideration to Ashland or to return all or a portion of the interest in MPC and the other assets we acquired from Ashland.

        Under the U.S. Bankruptcy Code and the laws of most states, a transaction could be held to be constructively fraudulent if a court determined that:

• the transferor received less than “reasonably equivalent value” or, in some jurisdictions, less than “fair consideration” or “valuable consideration;” and

25


• the transferor:
• was insolvent at the time of the transfer or was rendered insolvent by the transfer;
• was engaged, or was about to engage, in a business or transaction for which its remaining property constituted unreasonably small capital; or
• intended to incur, or believed it would incur, debts beyond its ability to pay as those debts matured.
        In connection with our recently completed transactions with Ashland completed in 2005, we delivered part of the overall consideration (specifically, shares of our common stock having a value of $915 million) to Ashland’sAshland's shareholders. In order to help establish that Ashland nevertheless received reasonably equivalent value or fair consideration from us in the transactions, we obtained a written opinion from a nationally recognized appraisal firm to the effect that Ashland received amounts that were reasonably equivalent to the combined value of Ashland’sAshland's interest in MPC and the other assets we acquired. We also obtained a favorable opinion from that appraisal firm relating to various financial tests that supported our conclusion and Ashland’sAshland's representation to us that Ashland was not insolvent either before or after giving effect to the closing of the transactions. Those opinions were based on specific information provided to itthe appraisal firm and were subject to various assumptions, including assumptions relating to Ashland’sAshland's existing and contingent liabilities and insurance coverages. Although we are confident in our conclusions regarding (1) Ashland’sAshland's receipt of reasonably equivalent value or fair consideration and (2) Ashland’sAshland's solvency, it should be noted that the

26



valuation of any business and a determination of the solvency of any entity involve numerous assumptions and uncertainties, and it is possible that a court could disagree with our conclusions.

If United States Steel fails to perform any of its material obligations to which we have financial exposure, we could be required to pay those obligations, and any such payment could materially reduce our cash flows and profitability and impair our financial condition.

        In connection with the separation of United States Steel from Marathon, United States Steel agreed to hold Marathon harmless from and against various liabilities. While we cannot estimate some of these liabilities, the portion of these liabilities that we can estimate amounts to $597$564 million as of December 31, 2005,2006, including accrued interest of $9$11 million. If United States Steel fails to satisfy any of those obligations, we would be required to satisfy them and seek indemnification from United States Steel. In that event, our indemnification claims against United States Steel would constitute general unsecured claims, effectively subordinate to the claims of secured creditors of United States Steel.

        Under applicable law and regulations, we also may be liable for any defaults by United States Steel in the performance of its obligations to pay federal income taxes, fund its ERISA pension plans and pay other obligations related to periods prior to the effective date of the separation.

        United States Steel hasSteel's senior unsecured debt is rated non-investment grade by two major credit ratings and has granted security interests in some of its assets.rating agencies. The steel business is highly competitive and a large number of industry participants have sought protection under bankruptcy laws in the past. The enforceability of our claims against United States Steel could become subject to the effect of any bankruptcy, fraudulent conveyance or transfer or other law affecting creditors’creditors' rights generally, or of general principles of equity, which might become applicable to those claims or other claims arising from the facts and circumstances in which the separation was effected.

If the transfer of ownership of various assets and operations by Marathon’sMarathon's former parent entity to Marathon was held to be a fraudulent conveyance or transfer, United States Steel’sSteel's creditors may be able to obtain recovery from us or other relief detrimental to the holders of our common stock.

        In July 2001, USX Corporation (“("Old USX”USX") effected a reorganization of the ownership of its businesses in which it created Marathon as its publicly owned parent holding company and transferred ownership of various assets and operations to Marathon, and it merged into a newly formed subsidiary which survived as United States Steel.

        If a court in a bankruptcy case regarding United States Steel or a lawsuit brought by its creditors or their representative were to find that, under the applicable fraudulent conveyance or transfer law:

• the transfer by Old USX to Marathon or related transactions were undertaken by Old USX with the intent of hindering, delaying or defrauding its existing or future creditors; or
• Old USX received less than reasonably equivalent value or fair consideration, or no value or consideration, in connection with those transactions, and either it or United States Steel
• was insolvent or rendered insolvent by reason of those transactions,

26


• was engaged or about to engage in a business or transaction for which its assets constituted unreasonably small capital, or
• intended to incur, or believed that it would incur, debts beyond its ability to pay as they mature,
then that court could determine those transactions entitled one or more classes of creditors of United States Steel to equitable relief from us. Such a determination could permit the unpaid creditors to obtain recovery from us or could result in other actions detrimental to the holders of our common stock. The measure of insolvency for purposes of these considerations would vary depending on the law of the jurisdiction being applied.

We may issue preferred stock whose terms could dilute the voting power or reduce the value of our common stock.

        Our restated certificate of incorporation authorizes us to issue, without the approval of our stockholders, one or more classes or series of preferred stock having such preferences, powers and relative, participating, optional and other rights, including preferences over our common stock respecting dividends and distributions, as our boardBoard of directorsDirectors generally may determine. The terms of one or more classes or series of preferred stock could dilute the voting power or reduce the value of our common stock. For example, we could grant holders of preferred stock the right to elect some number of our directors in all events or on the happening of specified events or the right to veto specified transactions. Similarly, the repurchase or redemption rights or liquidation preferences we could assign to holders of preferred stock could affect the residual value of the common stock.

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Item 1B. Unresolved Staff Comments

        As of the date of this filing, we have no unresolved comments from the staff of the Securities and Exchange Commission.

Item 2. Properties

Item 2. Properties

        The location and general character of the principal oil and gas properties, refineries, and gas plants, pipeline systems and other important physical properties of Marathon have been described previously. Except for oil and gas producing properties, which generally are leased, or as otherwise stated, such properties are held in fee. The plants and facilities have been constructed or acquired over a period of years and vary in age and operating efficiency. At the date of acquisition of important properties, titles were examined and opinions of counsel obtained, but no title examination has been made specifically for the purpose of this document. The properties classified as owned in fee generally have been held for many years without any material unfavorably adjudicated claim.

        The basis for estimating oil and gas reserves is set forth in “Financial"Financial Statements and Supplementary Data – Supplementary Information on Oil and Gas Producing Activities – Estimated Quantities of Proved Oil and Gas Reserves”Reserves" on pages F-46 through F-47.

F-46
throughF-47.

Property, Plant and Equipment Additions

        For property, plant and equipment additions, see “Management’s"Management's Discussion and Analysis of Financial Condition, Cash Flows and Liquidity – Capital Expenditures.

"

Item 3. Legal Proceedings

Item 3. Legal Proceedings

        Marathon is the subject of, or a party to, a number of pending or threatened legal actions, contingencies and commitments involving a variety of matters, including laws and regulations relating to the environment. Certain of these matters are included below. The ultimate resolution of these contingencies could, individually or in the aggregate, be material. However, management believeswe believe that Marathon will remain a viable and competitive enterprise even though it is possible that these contingencies could be resolved unfavorably.


Natural Gas Royalty Litigation

        As of December 31, 2005, Marathon washad been served in two qui tam cases, which allege that federal and Indian lessees violated the False Claims Act with respect to the reporting and payment of royalties on natural gas and natural gas liquids. The first case, U.S. ex rel Jack J. Grynberg v. Alaska Pipeline Co., et al is primarily a gas measurement case and the second case, U.S. ex rel Harrold E. Wright v. Agip Petroleum Co. et al, is primarily a gas valuation case. These cases assert that false claims have been filed by lessees and that penalties, damages and interest total more than $25 billion. The Department of Justice has announced that it would intervene or has reserved judgment on whether to intervene against specified oil and gas companies and also announced that it would not intervene against certain other defendants including Marathon. In the Grynberg case, the parties have briefed and argued their motions

27


regarding whether the District Court should adopt the recommendationsOne of the Magistratecases, U.S. ex rel Jack J. Grynberg v. Alaska Pipeline Co., et al, which would dismisswas primarily a gas measurement case, was dismissed as to Marathon and many other defendantson October 20, 2006 on jurisdictional grounds. The second case, U.S. ex rel Harrold E. Wright v. Agip Petroleum Co. et al, is primarily a gas valuation case. The Wright case is in the discovery phase.

        In October 2006, Marathon was served with an additional qui tam case, filed in the Western District of Oklahoma, which alleges that Marathon violated the False Claims Act by failing to pay the government past due interest resulting from royalty adjustments for crude oil, natural gas and other hydrocarbon production. The case is styled United States of America ex rel. Randy L. Little and Lanis G. Morris v. ENI Petroleum Co., et al. This case asserts that Marathon and other defendants are liable for past due interest, penalties, punitive damages and attorneys fees. Other than the specific allegation of underpayment for the month of May 2003 in the amount of $1,360, the parties in interest (Randy L. Little and Lanis G. Morris) have plead general damages with no other specific amounts against Marathon. Marathon intends to continue to vigorously defend these cases.


Powder River Basin Litigation

        The U.S. Bureau of Land Management (“BLM”("BLM") completed multi-year reviews of potential environmental impacts from coal bed methane development on federal lands in the Powder River Basin, including those in Wyoming. The BLM signed a Record of Decision (“ROD”("ROD") on April 30, 2003 supporting increased coal bed methane development. Plaintiff environmental and other groups filed suit in May 2003 in federal court against the BLM to stop coal bed methane development on federal lands in the Powder River Basin until the BLM conducted additional environmental impact studies. Marathon intervened as a party in the ongoing litigation before the Wyoming Federal District Court.

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        As these lawsuits to delay energy development in the Powder River Basin progress through the courts, the Wyoming BLM continues to process permits to drill under the ROD.

        In May 2004, plaintiff environmental groups Environmental Defense et al filed suit against the U.S. BLM in Montana Federal District Court, alleging the agency did not adequately consider air quality impacts of coal bed methane and oil and gas operations in the Powder River Basin in Montana and Wyoming when preparing its environmental impact statements. Plaintiffs request that the BLM be ordered to cease issuing leases and permits for energy development, until additional analysis of predicted air impacts is conducted. Marathon and its subsidiary Pennaco Energy, Inc. intervened in this litigation.


MTBE Litigation

        Marathon is a defendant along with many other refining companies in over 40 cases in 11 states alleging methyl tertiary-butyl ether (“MTBE”("MTBE") contamination in groundwater. All of these cases have been consolidated in a multi-district litigation in the Southern District of New York for preliminary proceedings. The judge in this multi-district litigation ruled on April 20, 2005 that some form of market share liability would apply. Market share liability enables a plaintiff to sue manufacturers who represent a substantial share of a market for a particular product and shift the burden of identification of who actually made the product to the defendants, effectively forcing a defendant to show that it did not produce the MTBE which allegedly caused the damage. The judge further allowed cases to go forward in New York and 11 other states, based upon varying theories of collective liability, and predicted that a new theory of market share liability would be recognized in Connecticut, Indiana and Kansas. The plaintiffs generally are water providers or governmental authorities and they allege that refiners, manufacturers and sellers of gasoline containing MTBE are liable for manufacturing a defective product and that the owners and operators of retail gasoline sites have allowed MTBE to be discharged into the groundwater. Several of these lawsuits allege contamination that is outside of Marathon’sMarathon's marketing area. A few of the cases seek approval as class actions. Many of the cases seek punitive damages or treble damages under a variety of statutes and theories. Marathon stopped producing MTBE at its refineries in October 2002. The potential impact of these recent cases and future potential similar cases is uncertain. The Company will defend these cases vigorously.

Acquisition Litigation
      On April 8, 2005, Shiva Singh instituted a class action in the Supreme Court of the State of New York in New York County against Ashland, and the individual members of Ashland’s Board of Directors. The complaint also named Marathon, MPC and Credit Suisse First Boston LLC (“CSFB”) as defendants. The complaint stated that Mr. Singh held Ashland common stock and that the complaint was brought on behalf of Mr. Singh and others similarly situated. The action arose from the transaction proposed at that time in which Ashland would transfer its entire 38 percent interest in MPC as well as certain other businesses to Marathon. The complaint alleged breach of fiduciary duty as well as aiding and abetting breach of fiduciary duty and negligence against Ashland, its directors, Marathon and MPC. The complaint alleged breach of fiduciary duty and negligence as well as aiding and abetting breach of fiduciary duty and negligence against CSFB.
     On September 20, 2005, the federal judge entered an order dismissing certain of the plaintiff’s negligence claims against CSFB and the aiding and abetting claims against all defendants and directed the court clerk to “mark the case closed.” This case is not currently pending.


Product Contamination Litigation

        A lawsuit was filed in the United States District Court for the Southern District of West Virginia and alleges that Marathon’sMarathon's Catlettsburg refinery sold defective gasoline to wholesalers and retailers, causing permanent damage to storage tanks, dispensers and related equipment, resulting in lost profits, business disruption and

28


personal and real property damages. Plaintiffs seek class action status. In 2002, MPC conducted extensive cleaning operations at affected facilities butand denies that any permanent damages resulted from the incident. MPC previously settled with many of the potential class members in this case and intends to vigorously defend this action.


Environmental Proceedings

U.S. EPA Litigation

        In 2002, Marathon and American Petroleum Institute ("API") brought a petition before the U.S. District Court for the District of Columbia, challenging the U.S. EPA's 2002 promulgation of new Oil Spill Prevention, Countermeasures and Control regulations on several grounds; while the dispute has been settled, the one remaining count is over the U.S. EPA's regulatory definition of waters covered by the Clean Water Act. Marathon and API contend that the U.S. EPA's regulations run contrary to recent decisions of the U.S. Supreme Court which, in finding federal agencies had gone greatly beyond the intentions of Congress as to what waters were covered by the Clean Water Act, narrowed the universe of what waters the federal government, rather than state governments, had jurisdiction to regulate.

        In September 2006, Marathon and other oil and gas companies joined the State of Wyoming in filing a Petition for Review against the U.S. EPA in the U.S. District Court for the District of Wyoming. These actions seek a Court order mandating the EPA to disapprove Montana's 2006 amended water quality standards, on grounds that the standards lack sound scientific justification, they are arbitrary and capricious, and were adopted contrary to law. These September 2006 actions have been consolidated with our pending April 2006 action against the U.S. EPA in the same Court. The water quality amendments at issue, if approved, could require more stringent discharge limits and have the potential to require certain Wyoming coal bed methane operations to perform more costly water treatment or inject produced water. Approval of these standards could delay or prevent obtaining permits needed to discharge produced water to streams flowing from Wyoming into Montana. The Court has stayed this case, and another filed in April 2006, until August 2007 while the U.S. EPA mediates the matter between Montana, Wyoming and the Northern Cheyenne tribe.

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Montana Litigation

        In June 2006, Marathon filed a complaint for declaratory judgment in Montana State District Court against the Montana Board of Environmental Review ("MBER") and the Montana Department of Environmental Quality, seeking to set aside and declare invalid certain regulations of the MBER that single out the coal bed natural gas industry and a few streams in eastern Montana for excessively severe and unjustified restrictions for surface water discharges of produced water from coal bed methane operations. None of the streams affected by the regulations suffers impairment from coal bed natural gas discharges.

Wyoming Proceedings

        The Wyoming Environmental Quality Council ("EQC"), which oversees the State Department of Environmental Quality ("DEQ"), has before it an administrative petition filed by the Powder River Basis Resource Council in 2006 seeking new water quality sulfate and barium standards for coal bed methane produced water and a requirement that all such water be beneficially reused. The petition seeks to expand the authority of DEQ to regulate the quantity of water discharges. It would narrow the definition of required "beneficial use" discharges and would impose stricter effluent standards for discharged water. The EQC is also considering adoption of a rule which would impose more stringent water quality limits as to produced water discharges that come from any new coal bed methane or conventional oil and gas operations. DEQ made this proposal citing a statutory directive that all waters that are suitable for agriculture may not be degraded. Marathon contends that its waters as currently regulated are beneficial to crops and livestock, rather than being a potential threat. The EQC would have to decide how stringent a water quality standard for new discharges it would adopt.

Other Proceedings

        The following is a summary of proceedings involving Marathon that were pending or contemplated as of December 31, 20052006 under federal and state environmental laws. Except as described herein, it is not possible to predict accurately the ultimate outcome of these matters; however, management’smanagement's belief set forth in the first paragraph under “Item"Item 3. Legal Proceedings”Proceedings" above takes such matters into account.

        Claims under CERCLA and related state acts have been raised with respect to the cleanup of various waste disposal and other sites. CERCLA is intended to facilitate the cleanup of hazardous substances without regard to fault. Potentially responsible parties (“PRPs”("PRPs") for each site include present and former owners and operators of, transporters to and generators of the substances at the site. Liability is strict and can be joint and several. Because of various factors including the difficulty of identifying the responsible parties for any particular site, the complexity of determining the relative liability among them, the uncertainty as to the most desirable remediation techniques and the amount of damages and cleanup costs and the time period during which such costs may be incurred, Marathon is unable to reasonably estimate its ultimate cost of compliance with CERCLA.

     Projections, provided in the following paragraphs,

        The projections of spending for and/or timing of completion of specific projects provided in the following paragraphs are forward-looking statements. These forward-looking statements are based on certain assumptions including, but not limited to, the factors provided in the preceding paragraph. To the extent that these assumptions prove to be inaccurate, future spending for or timing of completion of environmental projects may differ materially from those stated in the forward-looking statements.

     At

        As of December 31, 2005,2006, Marathon had been identified as a PRP at a total of sevennine CERCLA waste sites. Based on currently available information, which is in many cases preliminary and incomplete, Marathon believes that its liability for cleanup and remediation costs in connection with six of these sites will be under $1 million per site and most will be(with three of these six sites being under $100,000.$100,000 each). As to the remaining three sites of the nine, Marathon believes that its liability for cleanup and remediation costs in connection with the one remaining sitetwo of these sites will be under $3 million.

$4 million per site with the last site having costs that cannot be estimated at this time.

        In addition, there is one site whereare three sites for which Marathon has received information requests or other indications that it may be a PRP under CERCLA, but wherefor which sufficient information is not presently available to confirm the existence of liability.

        There are also 123 additional119 sites, excluding retail marketing outlets, related to Marathon where remediation is being sought under other environmental statutes, both federal and state, or where private parties are seeking remediation through discussions or litigation. Based on currently available information, which is in many cases preliminary and incomplete, Marathon believes that its liability for cleanup and remediation costs in connection with 2927 of these sites will be under $100,000 per site, 51that 45 sites have potential costs between $100,000 and $1 million per site and 18 that 19

30



sites may involve remediation costs between $1 million and $5 million per site. NineEleven sites have incurred remediation costs of more than $5 million per site and there are 1617 sites with insufficient information to estimate future remediation costs.

        There is one site that involves a remediation program in cooperation with the Michigan Department of Environmental Quality (“MDEQ”("MDEQ") at a closed and dismantled refinery site located near Muskegon, Michigan. During the next five30 years, Marathon anticipates spending approximately $5$7 million at this site. AppropriateIn 2007, interim remediation measures will occur and appropriate site characterization and risk-based assessments necessary for closure will be refined during 2006 and may change the estimated future expenditures for this site. The closure strategy being developed for this site and ongoing work at the site are subject to approval by the MDEQ. Expenditures in 2006 and 2005 were approximately$488,000 and $540,000, with expenditures in 20062007 expected to be $1approximately $2 million.

        MPC has had a pending enforcement matter with the Illinois Environmental Protection Agency and the Illinois Attorney General’sGeneral's Office since 2002 concerning its self-reporting of possible emission exceedences and permitting issues related to storage tanks at itsthe Robinson, Illinois refinery.

        In 2005, MPC anticipates more discussionsreceived a Notice of Violation from the U.S. EPA alleging 33 violations of Clean Air Act fuels requirements. The alleged violations largely resulted from MPC's attest engagements submitted to the Agency under the Reformulated Gasoline and Anti Dumping programs. In 2006, MPC reached an administrative settlement with Illinois officials in 2006.

     In August of 2004, the West Virginia Department of Environmental Protection (“WVDEP”) submitted a draft consent order toU.S. EPA where MPC regarding its handling of alleged hazardous waste generated from tank cleanings in the State of West Virginia. The proposed order soughtpaid a civil penalty of $337,900. MPC$139,000 and resolved this matterNotice of Violation.

        MPC received an enforcement action from the Minnesota Pollution Control Agency ("MPCA") in 2005 by entering an administrative order with WVDEPthe fourth quarter of 2006 where nothe MPCA seeks a civil penalty was imposed but MPC agreedof $121,800 for a release of catalyst from the fluid catalytic cracking unit at the St. Paul Park refinery in 2004 and other alleged violations. Discussions will be held with the MPCA in 2007 and the Company expects to pay $95,297 as an administrative settlement, a contribution toresolve the State Department of Natural Resources for park remediation efforts unrelated to this matter and a reimbursement of WVDEP’s costs.

within the year.

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SEC Investigation Relating to Equatorial Guinea

        By letter dated July 15, 2004, the United States Securities and Exchange Commission (“SEC”("SEC") notified Marathon that it was conducting an inquiry into payments made to the government of Equatorial Guinea, or to officials and persons affiliated with officials of the government of Equatorial Guinea. This inquiry followed an investigation and public hearing conducted by the United States Senate Permanent Subcommittee on Investigations, which reviewed the transactions of various foreign governments, including that of Equatorial Guinea, with Riggs Bank. The investigation and hearing also reviewed the operations of U.S. oil companies, including Marathon, in Equatorial Guinea. There was no finding in the Subcommittee’sSubcommittee's report that Marathon violated the U.S. Foreign Corrupt Practices Act or any other applicable laws or regulations. Marathon has been voluntarily producingproduced documents requested by the SEC in that inquiry. On August 1, 2005, Marathon received a subpoena issued by the SEC pursuant to a formal order of investigation requiring the production of the documents that havehad already been produced or that arewere in the process of being identified and produced in response to the SEC’sSEC's prior requests, and requesting the production of additional materials. Marathon has been and intends to continue cooperating with the SEC in this investigation.

Item 4. Submission of Matters to a Vote of Security Holders

Item 4. Submission of Matters to a Vote of Security Holders

        Not applicable.


PART II

Item 5. Market for Registrant’s Common Equity and Related Stockholder Matters and Issuer Purchase of Equity Securities
Item 5. Market for Registrant's Common Equity and Related Stockholder Matters and Issuer Purchase of Equity Securities

        The principal market on which Marathon’sMarathon's common stock is traded is the New York Stock Exchange. Marathon’sMarathon's common stock is also traded on the Chicago Stock Exchange and the Pacific Exchange. Information concerning the high and low sales prices for the common stock as reported in the consolidated transaction reporting system and the frequency and amount of dividends paid during the last two years is set forth in “Selected"Selected Quarterly Financial Data (Unaudited)" on page F-42.

        As of January 31, 2006,2007, there were 67,23064,646 registered holders of Marathon common stock.

        The Board of Directors intends to declare and pay dividends on Marathon common stock based on the financial condition and results of operations of Marathon Oil Corporation, although it has no obligation under Delaware law or the Restated Certificate of Incorporation to do so. In determining its dividend policy with respect to Marathon

31


common stock, the Board will rely on the consolidated financial statements of Marathon. Dividends on Marathon common stock are limited to legally available funds of Marathon.

        The following table provides information about purchases by Marathon and its affiliated purchaser during the quarter ended December 31, 20052006 of equity securities that are registered by Marathon pursuant to Section 12 of the Exchange Act:


ISSUER PURCHASES OF EQUITY SECURITIES

                 
  (a) (b) (c) (d)
      Total Number Maximum Number
      of Shares Purchased as of Shares that May
  Total Number of Average Part of Publicly Yet Be Purchased
  Shares Price Paid per Announced Plans or Under the Plans or
Period  Purchased(a)(b) Share Programs Programs
 
10/01/05 – 10/31/05  13,159  $59.00   N/A   N/A 
11/01/05 – 11/30/05  2,219  $60.86   N/A   N/A 
12/01/05 – 12/31/05  21,196(c) $61.78   N/A   N/A 
             
Total  36,574  $60.73   N/A   N/A 
 
(a)15,566 shares of restricted stock were delivered by employees to Marathon, upon vesting, to satisfy tax withholding requirements.
(b)Under the terms of the Acquisition, Marathon paid Ashland shareholders cash in lieu of issuing fractional shares of Marathon’s common stock to which such holder would otherwise be entitled. Marathon acquired 6 shares due to Acquisition exchanges and Ashland share transfers pending at the time of closing of the Acquisition.
(c)21,002 shares were repurchased in open-market transactions to satisfy the requirements for dividend reinvestment under the Marathon Oil Corporation Dividend Reinvestment and Direct Stock Purchase Plan (the “Plan”) by the administrator of the Plan. Stock needed to meet the requirements of the Plan are either purchased in the open market or issued directly by Marathon.

 
 (a)

 (b)

 (c)

 (d)

Period

 Total Number
of Shares
Purchased
(a)(b)

 Average Price
Paid per Share

 Total Number
of Shares
Purchased as
Part of Publicly
Announced Plans
or Programs
(d)

 Approximate Dollar Value of Shares that May Yet Be Purchased Under the Plans or Programs(d)

10/01/06 – 10/31/06 2,317,869 $79.90 2,302,642 $664,177,964
11/01/06 – 11/30/06 2,214,981 $89.01 2,212,358 $467,266,675
12/01/06 – 12/31/06 1,859,740(c)$94.13 1,815,000 $296,427,158
  
 
 
  
Total 6,392,590 $87.19 6,330,000  

(a)
46,872 shares of restricted stock were delivered by employees to Marathon, upon vesting, to satisfy tax withholding requirements.
(b)
Under the terms of the Acquisition, Marathon paid Ashland shareholders cash in lieu of issuing fractional shares of Marathon's common stock to which such holder would otherwise be entitled. Marathon acquired 7 shares due to Acquisition exchanges and Ashland share transfers pending at the time of closing of the Acquisition.
(c)
15,711 shares were repurchased in open-market transactions to satisfy the requirements for dividend reinvestment under the Marathon Oil Corporation Dividend Reinvestment and Direct Stock Purchase Plan (the "Plan") by the administrator of the Plan. Stock needed to meet the requirements of the Plan are either purchased in the open market or issued directly by Marathon.
(d)
In January 2006, we announced a $2 billion share repurchase program. In January 2007, our Board of Directors authorized the extension of this program by an additional $500 million. As of February 21, 2007, the Company had repurchased 24.2 million common shares at a cost of $2 billion.


Item 6. Selected Financial Data

(In millions, except per share data)

 2006(a)
 2005(a)
 2004
 2003
 2002

Statement of Income Data:               
Revenues(b) $64,896 $62,986 $49,465 $40,907 $31,295
Income from continuing operations  4,957  3,006  1,294  1,010  507
Net income  5,234  3,032  1,261  1,321  516
Basic per share data:               
 Income from continuing operations $13.85 $8.44 $3.85 $3.26 $1.63
 Net income $14.62 $8.52 $3.75 $4.26 $1.66
Diluted per share data:               
 Income from continuing operations $13.73 $8.37 $3.83 $3.25 $1.63
 Net income $14.50 $8.44 $3.73 $4.26 $1.66

Statement of Cash Flows Data:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
Capital expenditures from continuing operations $3,433 $2,796 $2,141 $1,873 $1,520
Dividends paid  547  436  348  298  285
Dividends paid per share $1.53 $1.22 $1.03 $0.96 $0.92

Balance Sheet Data as of December 31:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
Total assets $30,831 $28,498 $23,423 $19,482 $17,812
Total long-term debt, including capitalized leases  3,061  3,698  4,057  4,085  4,410

(a)
On June 30, 2005, Marathon acquired the 38 percent ownership interest in MPC previously held by Ashland, making it wholly-owned by Marathon. See Note 6 to the consolidated financial statements.
(b)
Effective April 1, 2006, Marathon changed its accounting for matching buy/sell transactions. This change had no effect on income from continuing operations or net income, but the revenues and cost of revenues recognized after April 1, 2006 are less than the amounts that would have been recognized under previous accounting practices. See Note 2 to the consolidated financial statements.

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Item 6. Selected Financial Data
      See page 

F-52.

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations

        Marathon is engaged in worldwide exploration, production and productionmarketing of crude oil and natural gas; domestic refining, marketing and transportation of crude oil and petroleum products, primarily in the Midwest, the upper Great Plains and southeastern United States; and worldwide marketing and transportation of natural gas and products manufactured from natural gas, such as LNG and methanol. Management’smethanol, and development of other projects to link stranded natural gas resources with key demand areas. Management's Discussion and Analysis of Financial Condition and Results of Operations should be read in conjunction with Item 1. Business, Item 1A. Risk Factors, Item 6. Selected Financial Data and Item 8. Financial Statements and Supplementary Data.

        Certain sections of Management’sManagement's Discussion and Analysis of Financial Condition and Results of Operations include forward-looking statements concerning trends or events potentially affecting our business. These statements typically contain words such as “anticipates,” “believes,” “estimates,” “expects,” “targets,” “plans,” “projects,” “could,” “may,” “should,” “would”"anticipates," "believes," "estimates," "expects," "targets," "plans," "projects," "could," "may," "should," "would" or similar words indicating that future outcomes are uncertain. In accordance with ”safe harbor”"safe harbor" provisions of the Private Securities Litigation Reform Act of 1995, these statements are accompanied by cautionary language identifying important factors, though not necessarily all such factors, which could cause future outcomes to differ materially from those set forth in the forward-looking statements.

        Unless specifically noted, amounts for MPCthe refining, marketing and transportation segment include the 38 percent interest in MPC held by Ashland prior to the Acquisition on June 30, 2005, and amounts for EGHoldingsthe integrated gas segment include the 25 percent interest held by GEPetrol,SONAGAS (previously held by GEPetrol) in all periods and the 8.5 percent interest held by Mitsui and the 6.5 percent interest held by Marubeni subsequent tosince July 25, 2005.

        Effective January 1, 2006, we revised our measure of segment income to include the effects of minority interests and income taxes related to the segments. In addition, the results of activities primarily associated with the marketing of our equity natural gas production, which had been presented as part of the Integrated Gas segment prior to 2006, are now included in the Exploration and Production segment. Segment results for all periods presented reflect these changes.


Overview

Exploration and Production

        Exploration and production segment revenues correlate closely with prevailing prices for the various qualities of crude oil and natural gas produced.we produce. The increase in our E&P segment revenues during 2005in 2006 is primarily related to increased production, particularly from Libya where the first liquid hydrocarbon sales occurred in the first quarter of 2006; however, our 2006 revenues also tracked the increasechanges in market prices for these commodities. Higher prices for crude oil during 2005early in 2006 reflected concerns about international supply due to unrest in oil-producing countries and the potential for hurricane damage in the U.S. Gulf of Mexico. As hurricane season came to an end without a major storm in the Gulf of Mexico and in the absence of significant international supply shortfalls or disruptions, crude oil prices declined. The average spot price during 20052006 for West Texas Intermediate (“WTI”("WTI"), a benchmark crude oil, was $56.70$66.25 per barrel, up from an average of $41.47$56.70 in 2004,2005, and ended the year at $61.04.$61.05. The average differential between WTI and Brent (an international benchmark crude oil) narrowed to $1.07 in 2006 from $2.18 in 2005 from $3.20 in 2004.2005. Our domestic crude oil production is on average heavier and higher in sulfur content than light sweet WTI. Heavier and higher sulfur crude oil (commonly referred to as heavy sour crude)crude oil) sells at a discount to light sweet crude oil. The majority of OPEC spare capacity and new production worldwide is medium sour or heavy sour, so the discount for medium and heavy sour crudes has increased relative to light sweetOur international crude and thus reduced the relative profitability of sour crude production. Outside of Russia, our international crudeoil production is relatively sweet and is generally sold in relation to the Brent crude benchmark.

        Natural gas prices were also higherlower in 20052006 compared to 2004.2005. A significant portion of our United States lower 48 natural gas production is sold at bid-week prices orfirst-of-month first-of-month indices relative to our specific producing areas. The average Henry Hub first-of-month price index was $1.41 per mcf lower in 2006 than the 2005 average. Our natural gas prices in Alaska are largely contractual, while natural gas productionsales there isare seasonal in nature, trending down during the second and third quarters of each year and increasing during the fourth and first quarters. Our other major natural gas-producing regions are Europe and Equatorial Guinea, where large portions of our natural gas are sold at contractual prices, making realized prices in these areas less volatile.

        For information on commodity price risk management, see “Item"Item 7A. Quantitative and Qualitative Disclosures about Market Risk.

"

        E&P segment income during 20052006 was up approximately 766 percent from 20042005 levels, impacted by higher product prices as discussed above and increased liquid hydrocarbon sales volumes. We estimate that our 2006volumes, primarily due to the resumption of production available for sale will average approximately 365,000 to 395,000 boe per day, excludingin Libya, and the impact of acquisitionshigher liquid

33



hydrocarbon prices discussed above, partially offset by higher income taxes, primarily in Libya, operating costs and dispositions. This includes an estimated 40,000 to 45,000 boe per day as a result of our return to operationsexploration expenses and decreases in the Waha concessions in Libya. With the developments we have under construction, we estimate our production will grow to 475,000 to 525,000 boe per day by 2008, excluding acquisitions and divestitures.

     Projected production levels for liquid hydrocarbons and natural gas are based on a number of assumptions, including (among others) pricing, supply and demand for petroleum products, the amount of capital available for exploration and development, regulatory constraints, production decline rates of mature fields, timing of commencing production from new wells, drilling rig availability, inability or delay in obtaining necessary government and third-party approvals and permits, unforeseen hazards such as weather conditions, acts of war or terrorist acts and the government or military response thereto, and other geological, operating and economic
sales volumes.

31


considerations. These assumptions may prove to be inaccurate. Prices have historically been volatile and have frequently been driven by unpredictable changes in supply and demand resulting from fluctuations in economic activity and political developments in the world’s major oil and gas producing areas, including OPEC member countries. Any substantial decline in such prices could have a material adverse effect on our results of operations. A decline in such prices could also adversely affect the quantity of liquid hydrocarbons and natural gas that can be economically produced and the amount of capital available for exploration and development.
Refining, Marketing and Transportation
     We refine, market and transport crude oil and petroleum products, primarily in the Midwest, upper Great Plains and southeastern United States.

        RM&T segment income depends largely on our refining and wholesale marketing gross margin, refinery throughputs, retail marketing gross margins for gasoline, distillates and merchandise, and the profitability of our pipeline transportation operations.

        The refining and wholesale marketing gross margin is the difference between the wholesale prices of refined products sold and the costcosts of crude oil and other feedstockscharge and blendstocks refined, the costcosts of purchased products and manufacturing costs.expenses, including depreciation. We purchase crude oil to satisfy our refineries’refineries' throughput requirements. As a result, our refining and wholesale marketing gross margin could be adversely affected by rising crude oil and other feedstockcharge and blendstock prices that are not recovered in the marketplace. The crack spread, which is generally a measure of the difference between spot market gasoline and distillate prices and spot market crude oil costs, is ana commonly used industry indicator of refining margins. In addition to changes in the crack spread, our refining and wholesale marketing gross margin is impacted by the types of crude oil and other charge and blendstocks we process, the wholesale selling prices we realize for all the refined products we sell, the cost of purchased product and our level of manufacturing costs. We process significant amounts of sour crude oil which enhances our competitive position in the industry as sour crude oil typically can be purchased at a discount to sweet crude oil. Over the last three years, approximately 60 percent of the crude oil throughput at our refineries has been sour crude oil. As one of the largest U.S. producerproducers of asphalt, our refining and wholesale marketing gross margin is significantlyalso impacted by the selling price of asphalt. Sales of asphalt increase during the highway construction season in our market area, which is typically in the second and third quarters.quarters of each year. The selling price of asphalt is dependent on the cost of crude oil, the price of alternative paving materials and the level of construction activity in both the private and public sectors. We supplement our refining production by purchasing gasolines and distillates in the spot market to resell at wholesale. In addition, we purchase ethanol for blending with gasoline. Our refining and wholesale marketing gross margin is impacted by the cost of these purchased products, which varies with available supply and demand. Finally, our refining and wholesale marketing gross margin is impacted by changes in manufacturing costs from period to period, which are primarily driven by the level of maintenance activities at the refineries and the price of purchased natural gas.gas used for plant fuel. Our refining and wholesale marketing gross margin has been historically volatile and varies with the level of economic activity in our various marketing areas, the regulatory climate, logistical capabilities and the expectations regarding the adequacy of the supply of refined productsproduct, ethanol and raw materials.

material supplies.

        Together with our June 30, 2005 acquisition of the 38 percent minority interest in MPC, our improved refining and wholesale marketing gross margin in 2006 was the key driver of the 72 percent increase in RM&T segment income over 2005. The average refining and wholesale marketing gross margin increased to 22.88 cents per gallon in 2006 from 15.82 cents per gallon in 2005.

        For information on commodity price risk management, see “Item"Item 7A. Quantitative and Qualitative Disclosures about Market Risk.

"

        Our seven refineries have an aggregate refining capacity of 974 mbpd of crude oil. During 2006, our refineries processed 980 mbpd of crude oil and 234 mbpd of other charge and blend stocks for a crude oil capacity utilization rate of 101 percent.

        Our retail marketing gross margin for gasoline and distillates, which is the difference between the ultimate price paid by consumers and the wholesale cost of the refined products, including secondary transportation and consumer excise taxes, also plays an important part in RM&T segment profitability. Factors affecting our retail gasoline and distillate gross margin include competition, seasonal demand fluctuations, the available wholesale supply, the level of economic activity in our marketing areas and weather situations that impact driving conditions. Gross margins on merchandise sold at retail outlets tend to be less volatile than the gross marginmargins from the retail sale of gasoline and diesel fuel.distillates. Factors affecting the gross margin on retail merchandise sales include consumer demand for merchandise items, the impact of competition and the level of economic activity in our marketing areas.

        The profitability of our pipeline transportation operations is primarily dependent on the volumes shipped through the pipelines. The volume of crude oil that we transport is directly affected by the supply of, and refiner demand for, crude oil in the markets served directly by our crude oil pipelines. Key factors in this supply and demand balance are the production levels of crude oil by producers, the availability and cost of alternative modes of transportation, and refinery and transportation system maintenance levels. The throughputvolume of the refined products that we transport is directly affected by the production levels of, and user demand for, refined products in the markets served

34



by our refined product pipelines. In most of our markets, demand for gasoline peaks during the summer driving season, which extends from May through September of each year, and declines during the fall and winter months. The seasonal pattern for distillates is the reverse of this, helping to level overall variability on an annual basis. As with crude oil, other transportation alternatives and system maintenance levels influence refined product movements.

Integrated Gas

        Our long-term integrated gas strategy is to link stranded natural gas resources with areas where a supply gap is emerging due to declining production and growing demand. LNG, particularly in regard to our operations in Equatorial Guinea, is a key component of thatthis integrated gas strategy. Our integrated gas operations include

32


marketing and transportation of natural gas and products manufactured from natural gas, such as LNG and methanol, primarily in the United States, Europe and West Africa. Also included in the financial results of the IG segment are the costs associated with ongoing development of certain integrated gas projects. The profitability of these operations depends largely on commodity prices, volume deliveries, margins on resale gas, and demand. Methanol spot pricing is volatile largely because global methanol demand is only 3335 million tons and any major unplanned shutdown of or addition to production capacity can have a significant impact on the supply-demand balance.


20052006 Operating Highlights

• We achieved exploration success with eight discoveries from 11 significant wells. We strengthened core E&P areas by:
• re-entering our operations in Libya;
• completing the Equatorial Guinea liquefied petroleum gas plant expansion project;
• progressing the Alvheim development offshore Norway to 43 percent completion; and
• obtaining approval for the Neptune development in the deepwater Gulf of Mexico.
• We added net proved oil and natural gas reserves of 282 million boe, excluding 2 million boe of dispositions, while producing 124 million boe during 2005. Over the past three years, we have added net proved reserves of 675 million boe, excluding dispositions of approximately 277 million boe, while producing approximately 385 million boe.
• We strengthened our RM&T business by:
• acquiring full ownership of our RM&T operations, with our acquisition of the 38 percent interest previously held by Ashland;
• completing the 26,000 bpd expansion of our Detroit refinery; and
• initiating FEED work for a potential 180,000 bpd expansion of our Garyville, Louisiana refinery.
• We achieved same store merchandise sales growth of 11.7 percent at Speedway SuperAmerica in 2005, which is the third consecutive year of double digit merchandise sales growth, and same store gasoline sales volume growth of 4.0 percent, which is the fourth consecutive year of better than one percent volume growth.
• We advanced our integrated gas strategy by:
• accelerating the EG LNG plant construction, such that the project is 66 percent complete at the end of 2005 with the first LNG shipments projected for the third quarter of 2007; and
• initiating an LNG supply contract to utilize our Elba Island, Georgia re-gasification terminal access rights.
• We increased the quarterly dividend 18 percent to 33 cents per share.

35



Critical Accounting Estimates

        The preparation of financial statements in accordance with generally accepted accounting principles requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the respective reporting periods. Actual results could differ from the estimates and assumptions used.

        Certain accounting estimates are considered to be critical if (1) the nature of the estimates and assumptions is material due to the levels of subjectivity and judgment necessary to account for highly uncertain matters or the susceptibility of such matters to change; and (2) the impact of the estimates and assumptions on financial condition or operating performance is material.

Estimated Net Recoverable Quantities of Oil and Natural Gas

        We use the successful efforts method of accounting for our oil and gas producing activities. The successful efforts method inherently relies on the estimation of proved oil and natural gas reserves, both developed and undeveloped. The existence and the estimated amount of proved reserves affect, among other things, whether certain costs are capitalized or expensed, the amount and timing of costs depreciated, depleted or amortized into net income and the presentation of supplemental information on oil and gas producing activities. Both the expected

33


future cash flows to be generated by oil and gas producing properties used in testing such properties for impairment and the expected future taxable income available to realize deferred tax assets also rely, in part, on estimates of net recoverable quantities of oil and natural gas.

        Proved reserves are the estimated quantities of oil and natural gas that geologic and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions. Estimates of proved reserves may change, either positively or negatively, as additional information becomes available and as contractual, economic and political conditions change. During 2005,2006, net revisions of previous estimates increased total proved reserves by 5883 million boe (five(6 percent of thebeginning-of-the-year beginning-of-the-year reserves estimate). Positive revisions of 8298 million boe were partially offset by 2415 million boe in negative revisions.

        Our estimation of net recoverable quantities of oil and natural gas is a highly technical process performed by in-house teams of reservoir engineers and geoscience professionals. All estimates prepared by these teams are made in compliance with SEC Rule 4-10(a)(2),(3) and (4) of Regulation S-X and Statement of Financial Accounting Standards ("SFAS") No. 25, "Suspension of Certain Accounting Requirements for Oil and Gas Producing Companies (an Amendment of FASB Statement No. 19)," and disclosed in accordance with the requirements of SFAS No. 69, "Disclosures about Oil and Gas Producing Activities (an Amendment of FASB Statements 19, 25, 33 and 39)." All reserve estimates are reviewed and approved by members of our Corporate Reserves Group. Any revisions ofchange to proved reserves estimates in excess of 2.5 million boe on a total-field basis, within a single month, must be approved by the Director of Corporate Reserves, who reports to our Chief Financial Officer. The Corporate Reserves Group audits recent acquisitionsmay also perform separate, detailed technical reviews of materialreserve estimates for significant fields andthat were acquired recently or for properties with problematic indicators such as excessively long lives, sudden changes in performance or changes in economic or operating conditions. In addition, third-party

        Third-party consultants are engaged to auditprepare independent reserve estimates with the stated objective of reviewing the topfor fields that make up 80 percent of our reserves over a three-yearrolling four-year period. Third-party auditsAt December 31, 2006 we had met this goal. For 2006, Marathon established a tolerance level of 10 percent for third-party reserve estimates such that the third-party consultants discontinue their estimation activities once their results are within 10 percent of Marathon's internal estimates. Should the third-party consultants' initial analysis fail to reach our tolerance level, the consultants re-examine the information provided, request additional data and refine their analysis if appropriate. If, after this re-examination, the third-party consultants cannot arrive at estimates within our tolerance, we would adjust our reserve estimates as necessary. This independent third-party reserve estimation process did not result in any significant changes to our reserve estimates duringin 2006, 2005 2004 and 2003.

or 2004.

        The reserves of the Alba field offshorein Equatorial Guinea comprise approximately 3940 percent of our total proved oil and natural gas reserves as of December 31, 2005. The reserves of the Waha concession in Libya that were acquired at the end of 2005 comprise approximately 13 percent of our total proved oil and natural gas reserves at that date.2006. The next five largest oil and gas producing asset groups – the Waha concessions in Libya, the Alvheim development offshore Norway, the Brae Area Complexarea complex offshore the United Kingdom, (“U.K.”), the Kenai field in Alaska and the Petronius developmentOregon Basin field in the GulfRocky Mountain area of Mexico and the East Kamennoye license in RussiaUnited States – comprise a total of approximately 1530 percent of our total proved oil and natural gas reserves.

36


        Depreciation and depletion of producing oil and natural gas properties is determined by theunits-of-production units-of-production method and could change with revisions to estimated proved developed reserves. The change in the depreciation and depletion rate over the past three years due to revisions of previous reserve estimates has not been significant. A five percent increase in the amount of oil and natural gas reserves would change the depreciation and depletion rate from $6.04$6.92 per barrel to $5.75$6.59 per barrel, which would increase pretax income by approximately $36$45 million annually, based on 20052006 production. A five percent decrease in the amount of oil and natural gas reserves would change the depreciation and depletion rate from $6.04$6.92 per barrel to $6.36$7.28 per barrel and would result in a decrease in pretax income of approximately $40$50 million annually, based on 20052006 production.

Fair Value Estimates

        We are required to develop estimates of fair value to allocate the purchase prices paid to acquire businesses to the assets acquired and liabilities assumed in those acquisitions, to assess impairment of long-lived assets, goodwill and goodwillintangible assets and to record non-exchange traded derivative instruments. Other items which require estimates of fair value estimates include asset retirement obligations, guarantee obligations and stock-based compensation.

        Under the purchase method of accounting, the purchase price paid to acquire a business is allocated to its assets and liabilities based on the estimated fair values of the assets acquired and liabilities assumed as of the date of acquisition. The excess of the purchase price over the fair value of the net tangible and identifiable intangible assets acquired is recorded as goodwill. The most difficult estimations of individual fair values are those involving property, plant and equipment and identifiable intangible assets. We use all available information to make these fair value determinations and, for certain acquisitions, engage third-party consultants for assistance. During 2005, we made two significant acquisitions with an aggregate purchase price of $3.153$3.156 billion that was allocated to the assets acquired and liabilities assumed based on their estimated fair values. See Note 56 to the consolidated financial statements for information on these acquisitions. We did not make any significant acquisitions in 2006. As of December 31, 2005, we have2006, our recorded goodwill of $1.307was $1.398 billion. Such goodwill is not amortized, but rather is tested for impairment annually, and when events or changes in circumstances indicate that the fair value of a reporting unit with goodwill has been reduced below its carrying value.

        The fair values used to allocate the purchase pricesprice of acquisitionsan acquisition and to test goodwill for impairment are often estimated using the expected present value of future cash flows method, which requires us to project related future revenues and expenses and apply an appropriate discount rate. The estimates used in determining fair values are based on assumptions believed to be reasonable but which are inherently uncertain and unpredictable. Accordingly, actual results may differ from the projected results used to determine fair value.

34


        Long-lived assets used in operations are assessed for impairment whenever changes in facts and circumstances indicate that the carrying value of the assets may not be recoverable. For purposes of impairment evaluation, long-lived assets must be grouped at the lowest level for which independent cash flows can be identified, which generally is field-by-field for E&P assets, refinery and associated distribution system level or pipeline system level for refining and transportation assets, or site level for retail stores. If the sum of the undiscounted estimated pretax cash flows is less than the carrying value of an asset group, the carrying value is written down to the estimated fair value.

        Estimating the expected future cash flows from our oil and gas producing asset groups requires assumptions about matters such as future oil and natural gas prices, estimated recoverable quantities of oil and natural gas, expected field performance and the political environment in the host country. An impairment of any of our large oil and gas producing properties could have a material impact on our consolidated financial condition and results of operations.

        We evaluate our unproved property investment for impairment based on time or geologic factors in addition to the use of an undiscounted future net cash flow approach. Information such as drilling results, reservoir performance, seismic interpretation or future plans to develop acreage are also considered. The expected future cash flows from our RM&T assets require assumptions about matters such as future refined product prices, future crude oil and other feedstock costs, estimated remaining lives of the assets and future expenditures necessary to maintain the assets’assets' existing service potential.

        During 2006, we recorded impairments of $25 million, including $20 million related to the Camden Hills field in the Gulf of Mexico and the associated Canyon Express pipeline. Natural gas production from the Camden Hills field ended during 2006 as a result of increased water production from the well. We did not have significant impairment charges during 2005 or 2003.2005. During 2004, we recorded an impairment of $32 million related to unproved properties and $12 million related to producing properties primarily as a result of unsuccessful developmental drilling activity in Russia.

37



        We record all derivative instruments at fair value. We have two long-term contracts for the sale of natural gas in the U.K. whichUnited Kingdom that are accounted for as derivative instruments. These contracts expire in September 2009. These contracts were entered into in the early 1990s in support of our investments in the East Brae field and the SAGE pipeline. Contract prices are linked to a basket of energy and other indices. The contract price is reset annually in October based on the previous twelve-month changes in the basket of indices. Consequently, the prices under these contracts do not track forward natural gas prices. The fair value of these contracts is determined by applying the difference between the contract price and the U.K. forward natural gas strip price to the expected sales volumes under these contracts for the next eighteen months under these contracts.18 months. Adjustments to the fair value of these contracts result in non-cash charges or credits to income from operations. The difference between the contract price and the U.K. forward natural gas strip price may fluctuate widely from time to time and may significantly affect income from operations. TheIn 2006, the non-cash lossesgains related to changes in fair value recognized in income from operations were $454 million. Non-cash losses of $386 million and $99 million were recognized in 2005 $99 million in 2004, and $66 million in 2003.2004. These effects are primarily due to the U.K.18-month forward natural gas price curve strengtheningweakening 44 percent in 2006, while it strengthened 90 percent 36 percent and 2636 percent during 2005 2004 and 2003, respectively.

2004.

Expected Future Taxable Income

        We must estimate our expected future taxable income to assess the realizability of our deferred income tax assets. As of December 31, 2005,2006, we reported net deferred tax assets of $1.782$1.865 billion, which represented gross assets of $2.409$2.554 billion net of valuation allowances of $627$689 million.

        Numerous assumptions are inherent in the estimation of future taxable income, including assumptions about matters that are dependent on future events, such as future operating conditions (particularly as related to prevailing oil and natural gas prices) and future financial conditions. The estimates and assumptions used in determining future taxable income are consistent with those used in our internal budgets, forecasts and strategic plans.

        In determining our overall estimated future taxable income for purposes of assessing the need for additional valuation allowances, we consider proved and risk-adjusted probable and possible reserves related to our existing producing properties, as well as estimated quantities of oil and natural gas related to undeveloped discoveries if, in our judgment, it is likely that development plans will be approved in the foreseeable future. In assessing the propriety of releasing an existing valuation allowance, we consider the preponderance of evidence concerning the realization of the impaired deferred tax asset.

        Additionally, we must consider any prudent and feasible tax planning strategies that might minimize the amount of deferred tax liabilities recognized or the amount of any valuation allowance recognized against deferred tax assets, if we can implement these strategies and if we expect to implement these strategies in the event the forecasted conditions actually occurred. The principal tax planning strategy available to us relates to the permanent reinvestment of the earnings of our foreign subsidiaries. Assumptions related to the permanent reinvestment of the earnings of our foreign subsidiaries are reconsidered quarterly to give effect to changes in our portfolio of producing properties and in our tax profile.

35


Pensions and Other Postretirement Benefit Obligations

        Accounting for pension and other postretirement benefit obligations involves numerous assumptions, the most significant of which relate to the following:

• discount rate for measuring the present value of future plan obligations;
• expected long-term rates of return on plan assets;
• rate of future increases in compensation levels; and
• health care cost projections.

        We develop our demographics and utilize the work of third-party actuaries to assist in the measurement of these obligations. We have selected different discount rates for our funded U.S. pension plans and our unfunded U.S. retiree health plans due to the different projected liability durations of nine9 years and 13 years. In determining the assumed discount rates, our methods include a review of market yields on high-quality corporate debt and use of our third-party actuary’sactuary's discount rate modeling tool. This tool applies a yield curve to the projected benefit plan cash flows using a hypothetical Aa yield curve. The yield curve represents a series of annualized individual discount rates from 1.5 to 30 years. The bonds used are rated Aa or higher by a recognized rating agency and only non-callable bonds are included. Each issue is required to have at least $150 million par value outstanding. The top quartile bonds are selected within each maturity group to construct the yield curve.

38



        The asset rate of return assumption considers the asset mix of the plans (currently targeted at approximately 75 percent equity securities and 25 percent debt securities for the funded U.S. pension plans), past performance and other factors. Certain components of the asset mix are modeled with various assumptions regarding inflation, debt returns and stock yields. Our assumptions are compared to those of peer companies and to historical returns for reasonableness.

reasonableness and appropriateness.

        Compensation increase assumptions are based on historical experience, anticipated future management actions and demographics of the benefit plans.

        Health care cost trend assumptions are developed based on historical cost data, the near-term outlook and an assessment of likely long-term trends.

        Note 2324 to the consolidated financial statements includes detailed information forabout the three years ended December 31, 2005, onassumptions used to calculate the components of our defined benefit pension and other postretirement benefitplan expense for 2006, 2005 and 2004, as well as the underlying assumptions.

obligations and accumulated other comprehensive income reported on the balance sheets as of December 31, 2006 and 2005.

        Of the assumptions used to measure the December 31, 20052006 obligations and estimated 20062007 net periodic benefit cost, the discount rate has the most significant effect on the periodic benefit costscost reported for the plans. A ..250.25 percent decrease in the discount rates of 5.505.80 percent for our domesticU.S. pension planplans and 5.755.90 percent for our domesticother U.S. postretirement benefit plans would increase pension obligations and other postretirement benefit plan obligations by $93 million and $28 million and would increase defined benefit pension expense and other postretirement benefit plan expense by approximately $13 million and $3 million, respectively.

$2 million.

        In 2006, we made certain plan design changes which included an update of the mortality table used in the plans' definition of actuarial equivalence and lump sum calculations and a 20 percent retiree cost of living adjustment for annuitants. This change increased our benefit obligations by $117 million. In 2005, we decreased our retirement age assumption by two years and also increased our lump sum election rate from 90 percent to 96 percent based on changing trends in our experience. This change increased our benefit obligations by approximately $109 million.

Contingent Liabilities

        We accrue contingent liabilities for income and other tax deficiencies, environmental remediation, product liability claims and litigation claims when such contingencies are probable and estimable. Actual costs can differ from estimates for many reasons. For instance, the costs from settlement of claims and litigation can vary from estimates based on differing interpretations of laws, opinions on responsibility and assessments of the amount of damages. Similarly, liabilities for environmental remediation may vary because of changes in laws, regulations and their interpretation; the determination of additional information on the extent and nature of site contamination; and improvements in technology. Our in-house legal counsel regularly assesses these contingent liabilities. In certain circumstances, outside legal counsel is utilized.

        A liability is recorded for these types of contingencies if we determine the loss to be both probable and estimable. We generally record these losses as “Costcost of revenues”revenues or “Selling,selling, general and administrative expenses”expenses in the consolidated statements of income, except for tax contingencies, which are recorded as “Other taxes”other taxes or “Provisionprovision for income taxes. For additional information on contingent liabilities, see “Management’s"Management's Discussion and Analysis of Environmental Matters, Litigation and Contingencies.

"

        An estimate as toof the sensitivity to earningsnet income if other assumptions had been used in recording these liabilities is not practical because of the number of contingencies that must be assessed, the number of underlying assumptions

36


and the wide range of reasonably possible outcomes, in terms of both the probability of loss and the estimates of such loss.


Management’sManagement's Discussion and Analysis of IncomeResults of Operations

Change in Accounting for Matching Buy/Sell Transactions

        Matching buy/sell transactions arise from arrangements in which we agree to buy a specified quantity and quality of crude oil or refined product to be delivered to a specified location while simultaneously agreeing to sell a specified quantity and quality of the same commodity at a specified location to the same counterparty. Prior to April 1, 2006, all matching buy/sell transactions were recorded as separate sale and purchase transactions, or on a "gross" basis. Effective for contracts entered into or modified on or after April 1, 2006, the income effects of matching buy/sell

39



transactions are reported in cost of revenues, or on a "net" basis. Transactions under contracts entered into before April 1, 2006 will continue to be reported on a "gross" basis.

        Each purchase and sale transaction has the characteristics of a separate legal transaction, including separate invoicing and cash settlement. Accordingly, we believed that we were required to account for these transactions separately. An accounting interpretation clarified the circumstances under which a matching buy/sell transaction should be viewed as a single transaction involving the exchange of inventory. For a further description of the accounting requirements and how they apply to matching buy/sell transactions, see Note 2 to the consolidated financial statements.

        This accounting change had no effect on net income but the amounts of revenues and cost of revenues recognized after April 1, 2006 are less than the amounts that would have been recognized under previous accounting practices.

        Additionally, this accounting change impacts the comparability of certain operating statistics, most notably "refining and wholesale marketing gross margin per gallon." While this change does not have an effect on the refining and wholesale marketing gross margin (the numerator for calculating this statistic), sales volumes (the denominator for calculating this statistic) recognized after April 1, 2006 are less than the amount that would have been recognized under previous accounting practices because volumes related to matching buy/sell transactions under contracts entered into or modified on or after April 1, 2006 have been excluded. Accordingly, the resulting refining and wholesale marketing gross margin per gallon statistic will be higher than that same statistic calculated from amounts determined under previous accounting practices. The effect of this change on the refining and wholesale marketing gross margin per gallon for 2006 was not significant.

Consolidated Results of Operations

Revenuesfor each of the last three years are summarized in the following table:

                
(In millions) 2005 2004 2003
 
E&P $6,486  $4,996  $4,877 
RM&T  56,003   43,630   34,514 
IG  2,084   1,739   2,248 
          
   Segment revenues  64,573   50,365   41,639 
Elimination of intersegment revenues  (876)  (668)  (610)
Loss on long-term U.K. gas contracts  (386)  (99)  (66)
          
   Total revenues $63,311  $49,598  $40,963 
          
Items included in both revenues and costs and expenses:            
 Consumer excise taxes on petroleum products and merchandise $4,715  $4,463  $4,285 
 Matching crude oil and refined product buy/sell transactions settled in cash:            
  E&P $123  $167  $222 
  RM&T  12,513   9,075   6,961 
          
   Total buy/sell transactions included in revenues $12,636  $9,242  $7,183 
 

(In millions)

 2006
 2005
 2004
 

 
E&P $9,010 $8,009 $6,412 
RM&T  55,941  56,003  43,630 
IG  179  236  190 
  
 
 
 
 Segment revenues  65,130  64,248  50,232 
Elimination of intersegment revenues  (688) (876) (668)
Gain (loss) on long-term U.K. gas contracts  454  (386) (99)
  
 
 
 
 Total revenues $64,896 $62,986 $49,465 
  
 
 
 
 
Items included in both revenues and costs and expenses:

 

 

 

 

 

 

 

 

 

 

Consumer excise taxes on petroleum products and merchandise

 

$

4,979

 

$

4,715

 

$

4,463

 
Matching crude oil and refined product buy/sell transactions settled in cash:          
 E&P $16 $123 $167 
 RM&T  5,441  12,513  9,075 
  
 
 
 
   Total buy/sell transactions included in revenues $5,457 $12,636 $9,242 

 

E&P segment revenues increased $1.001 billion in 2006 from 2005 and $1.597 billion in 2005 from 2004. The 2006 increase was primarily in international revenues due to higher realized liquid hydrocarbon prices and sales volumes as illustrated in the table below. The largest liquid hydrocarbon sales volume increase was in Libya, where the first crude oil sales occurred in the first quarter of 2006 and where sales volumes averaged 54 mbpd in 2006, including a total of 8 mbpd that were owed to our account upon the resumption of our operations there. Revenues from domestic operations were flat from year to year. An 8 percent decrease in domestic net natural gas sales volumes, primarily as the result of the Camden Hills field in the Gulf of Mexico ceasing production in early 2006, almost completely offset the benefit of higher liquid hydrocarbon prices in 2006.

        The 2005 increase in E&P segment revenues increased by $1.490 billion in 2005 fromover 2004 and by $119 million in 2004 from 2003. The 2005 increase was primarily due tothe result of higher worldwide liquid hydrocarbon and natural gas prices and international liquid hydrocarbon sales volumes partially offset by lower domestic natural gas and liquid hydrocarbon sales volumes. Derivativevolumes as illustrated in the table below. The decline in domestic

40



volumes in 2005 resulted primarily from weather-related downtime in the Gulf of Mexico and natural declines in field production rates.

 
 2006
 2005
 2004

E&P OPERATING STATISTICS         
Net Liquid Hydrocarbon Sales (mbpd)(a)         
 United States  76  76  81
 
Europe

 

 

35

 

 

36

 

 

40
 Africa  112  52  32
  
 
 
  Total International(b)  147  88  72
  
 
 
  Worldwide Continuing Operations  223  164  153
  Discontinued Operations(c)  12  27  17
  
 
 
  Worldwide  235  191  170
Net Natural Gas Sales (mmcfd)(d)(e)         
 United States  532  578  631
 
Europe

 

 

243

 

 

262

 

 

292
 Africa  72  92  76
  
 
 
  Total International  315  354  368
  
 
 
  Worldwide  847  932  999
Total Worldwide Sales (mboepd)         
 Continuing operations  365  319  320
 Discontinued operations  12  27  17
  
 
 
  Worldwide  377  346  337

Average Realizations(f)         
 Liquid Hydrocarbons ($per bbl)         
  United States $54.41 $45.41 $32.76
  
Europe

 

 

64.02

 

 

52.99

 

 

37.16
  Africa  59.83  46.27  35.11
   Total International  60.81  49.04  36.24
   Worldwide Continuing Operations  58.63  47.35  34.40
   Discontinued Operations  38.38  33.47  22.65
   Worldwide $57.58 $45.42 $33.31
 
Natural Gas ($per mcf)

 

 

 

 

 

 

 

 

 
  United States $5.76 $6.42 $4.89
  
Europe

 

 

6.74

 

 

5.70

 

 

4.13
  Africa  0.27  0.25  0.25
   Total International  5.27  4.28  3.33
   
Worldwide

 

$

5.58

 

$

5.61

 

$

4.31

(a)
Includes crude oil, condensate and natural gas liquids.
(b)
Represents equity tanker liftings and direct deliveries of liquid hydrocarbons. The amounts correspond with the basis for fiscal settlements with governments. Crude oil purchases, if any, from host governments are excluded.
(c)
Represents Marathon's Russian oil exploration and production businesses that were sold in June 2006.
(d)
Represents net sales after royalties, except for Ireland where amounts are before royalties.
(e)
Includes natural gas acquired for injection and subsequent resale of 46, 38, and 19 mmcfd in 2006, 2005 and 2004, respectively. Effective July 1, 2005, the methodology for allocating sales volumes between natural gas produced from the Brae complex and third-party natural gas production was modified, resulting in an increase in volumes representing natural gas acquired for injection and subsequent resale.
(f)
Excludes gains and losses included inon traditional derivative instruments and the unrealized effects of long-term U.K. natural gas contracts that are accounted for as derivatives.

        E&P segment revenues totaled $5included derivative gains of $25 million and $7 million in 2006 and 2005, $169and derivative losses of $152 million in 2004 and $110 million in 2003.2004. Excluded from E&P segment revenues were gains of $454 million in 2006 and losses of $386 million in 2005,and $99 million in 20042005 and $66 million in 20032004 related to long-term natural gas sales contracts in the U.K.United Kingdom that are accounted for as derivative instruments. See “Item"Item 7A. Quantitative and Qualitative Disclosures about Market Risk”Risk" on page 53. Matching buy/sell transactions decreased by $44 million in 2005 from 2004 and by $55 million in 2004 from 2003. The 2005 and 2004 decreases were primarily due to decreased crude oil buy/sell volumes, partially offset by higher domestic liquid hydrocarbon prices.

56.

RM&T segment revenues decreased by $62 million in 2006 from 2005 and increased by $12.373 billion in 2005 from 20042004. The portion of RM&T revenues reported for matching buy/sell transactions decreased $7.072 billion and by $9.116increased $3.438 billion in 2004the same periods. The decrease in revenues from 2003.matching buy/sell transactions in 2006 was a result of the change in accounting for these transactions effective April 1, 2006, discussed above. Excluding matching buy/sell transactions, 2006 revenues increased primarily as a result of higher refined product prices and

41



sales volumes. The 2005 increase primarily reflected higher refined product and crude oil prices and increased refined product sales volumes, partially offset by decreased crude oil sales volumes. The 2004 increase primarily reflected higher refined product and crude oil prices and increased refined product and crude oil sales volumes. Matching buy/sell transactions increased by $3.438 billion in 2005 from 2004 and by $2.114 billion in 2004 from 2003. The 2005 and 2004 increases were primarily due to increased crude oil prices and volumes and higher refined product prices and volumes.

     IG segment revenues increased by $345 million in 2005 from 2004 and decreased by $509 million in 2004 from 2003. The increase in 2005 is a result of higher natural gas prices. The decrease in 2004 is due to a decrease in natural gas marketing activities, partially offset by higher natural gas prices. Derivative gains included in IG segment revenues totaled $13 million in 2005, compared to gains of $17 million in 2004 and $19 million in 2003.

        For additional information on segment results see the discussion on income from operations on page 39.

43.

Income from equity method investmentsincreased by $96$126 million in 2006 from 2005 and increased by $98 million in 2005 from 2004 and by $141 million2004. Income from our LPG operations in 2004 from 2003.Equatorial Guinea increased in both periods due to higher sales volumes as a result of the plant expansions completed in 2005. The increase in 2005 is primarily due toalso included higher PTC income from Alba Plant, LLC as a result of higher LPG and condensate production volume and higher income from PTC as a result of higher distillate gross margins. The increase in 2004 resulted from a $124 million loss on the dissolution of MKM Partners L.P. recorded in 2003. Results for 2004 also include increased earnings of other equity method investments, primarily AMPCO.

Cost of revenuesincreased by $7.107$4.609 billion in 2006 from 2005 and $7.106 billion in 2005 from 2004 and by $5.840 billion in 2004 from 2003. The2004. In both periods the increases arewere primarily in the RM&T segment and resulted from an increaseincreases in acquisition costs forof crude oil, an increase in the cost of refined product purchases, an increase in the cost of other refinery charge and blend stocks and purchased refined products. The increase in both periods was also impacted by higher manufacturing expenses, primarily the result of higher contract services and labor costs in 2006 and higher purchased energy and depreciation.

costs in 2005.

Purchases related to matching buy/sell transactions decreased $6.968 billion in 2006 from 2005 and increased by $3.314 billion in 2005 from 2004, and $1.837 billion in 2004 from 2003, primarilymostly in the RM&T segment. The increasesdecrease in 2006 was primarily related to the change in accounting for matching buy/sell transactions discussed above. The increase in 2005 was primarily due to increased crude oil prices.

Depreciation, depletion and amortization increased $215 million in 2006 from 2005 and $125 million in 2005 from 2004. RM&T segment depreciation expense increased in both years are primarily dueas a result of the increase in asset value recorded for our acquisition of the 38 percent interest in MPC on June 30, 2005. In addition, the Detroit refinery expansion completed in the fourth quarter of 2005 contributed to

37


increased crude oil prices. Differences between revenues from matching buy/sell transactions and purchases the RM&T depreciation expense increase in 2006. E&P segment depreciation expense for 2006 included a $20 million impairment of capitalized costs related to matching buy/sell transactions are primarily grade/qualitythe Camden Hills field in the Gulf of Mexico and location differentials.
the associated Canyon Express pipeline. Natural gas production from the Camden Hills field ended in 2006 as a result of increased water production from the well.

Selling, general and administrative expensesincreased by $133$73 million in 2006 from 2005 and $134 million in 2005 from 20042004. The 2006 increase was primarily because personnel and by $105 millionstaffing costs increased throughout the year primarily as a result of variable compensation arrangements and increased business activity. Partially offsetting these increases were reductions in 2004 from 2003.stock-based compensation expense. The increase in 2005 was primarily a result of increased stock-based compensation expense, due to the increase in theour stock price during thethat year as well as an increase in equity-based awards. Thisawards, which was partially offset by a decrease in expense as a result of severance and pension plan curtailment charges andstart-up costs related to EGHoldings in 2004. The increase

Exploration expenses increased $148 million in 2004 was primarily due to increased stock-based compensation2006 from 2005 and higher costs associated with business transformation and outsourcing. Our 2004 results were also impacted by thestart-up costs discussed above and the increased cost of complying with governmental regulations.

Other taxesincreased by $144$59 million in 2005 from 20042004. Exploration expense related to dry wells and increased $39other write-offs totaled $166 million, $111 million and $47 million in 2004 from 2003. The increase2006, 2005 and 2004. Exploration expense in 2005 is primarily a result of increased payments of mineral extraction tax2006 also included $47 million for exiting the Cortland and export dutyEmpire leases in Russia due to higher sales volumes and crude oil prices.
Nova Scotia.

Net interest and other financialfinancing costs (income) reflected a net $37 million of income for 2006, a favorable change of $183 million from the net $146 million expense in 2005. Net interest and other financing costs decreased by $16 million in 2005 from 20042004. The favorable changes in 2006 included increased interest income due to higher interest rates and by $25 million in 2004 from 2003.average cash balances, foreign currency exchange gains, adjustments to interest on tax issues and greater capitalized interest. The decrease in expense for 2005 iswas primarily a result of increased interest income on higher average cash balances and greater capitalized interest, partially offset by increased interest on potential tax deficiencies and higher foreign exchange losses. The decrease in 2004 is primarily due to an increase in interest income on higher cash balances. Included in net interest and other financing costs (income) are foreign currency gains of $16 million, losses of $17 million and gains of $9 million for 2006, 2005 and $13 million for 2005, 2004 and 2003.

2004.

Minority interest in income of MPCdecreased by $148 million in 2005 from 2004 due to theour acquisition of Ashland’sthe 38 percent interest in MPC on June 30, 2005.

Provision for income taxesincreased by $1.003$2.308 billion in 2006 from 2005 and $979 million in 2005 from 2004, and by $143 million in 2004 from 2003, primarily due to $2.797the $4.259 billion and $388 million$2.691 billion increases in income from continuing operations before income taxes.

The increase in our effective income tax rate for 2005in 2006 was 36.2 percent comparedprimarily a result of the income taxes related to 36.6 percent for both 2004 and 2003.our Libyan operations, where the statutory income tax rate is in excess of 90 percent. The following is an analysis of the effective income tax raterates for continuing operations for 2006, 2005 and 2004. See Note 11 to the periods presented:
              
  2005 2004 2003
 
Statutory tax rate  35.0%  35.0%  35.0%
Effects of foreign operations  (0.9)  1.3   (0.4)
State and local income taxes after federal income tax effects  2.5   1.6   2.2 
Other federal tax effects  (0.4)  (1.3)  (0.2)
          
 Effective tax rate  36.2%  36.6%  36.6%
 
consolidated financial statements for further discussion.

 
 2006
 2005
 2004
 

 
Statutory U.S. income tax rate 35.0%35.0%35.0%
Effects of foreign operations, including foreign tax credits 9.9 (0.8)0.5 
State and local income taxes net of federal income tax effects 1.9 2.5 1.6 
Other tax effects (2.0)(0.4)(0.9)
  
 
 
 
 Effective income tax rate for continuing operations 44.8%36.3%36.2%

 

42


Discontinued operationsin 2004 for all periods reflects the operations of our former Russian oil exploration and 2003 primarily relates to our E&P operations in western Canada,production businesses which were sold in 2003June 2006. An after-tax gain on the disposal of $243 million is included in discontinued operations for a gain of $278 million, including a tax benefit of $8 million.2006. See Note 7 to the consolidated financial statements for additional information. Also included in 2003 results2004 is an $8a $4 million adjustment to a tax liability due to United States Steel Corporation.

the gain on the 2003 sale of our exploration and production operations in western Canada.

Cumulative effect of changeschange in accounting principlesprinciplein 2005 was an unfavorable effect of $19 million, net of taxes of $12 million, representing the adoption of Financial Accounting Standards Board Interpretation (“FIN”("FIN") No. 47, “Accounting"Accounting for Conditional Asset Retirement Obligations – an interpretation of FASB Statement No. 143," as of December 31, 2005.

Segment Results

        Effective January 1, 2006, we revised our measure of segment income to include the effects of minority interests and income taxes related to the segments. In addition, the results of activities primarily associated with the marketing of our equity natural gas production, which had been presented as part of the integrated gas segment prior to 2006, are now included in the exploration and production segment. Segment results for all periods presented reflect these changes.

        As discussed in Note 7 to the consolidated financial statements, we sold our Russian oil exploration and production businesses during 2006. The cumulative effectactivities of a change in accounting principle in 2003 was a favorable effect of $4 million, net of taxes of $4 million, representing the adoption of Statement of Financial Accounting Standards (“SFAS”) No. 143, “Accountingthese operations have been reported as discontinued operations and therefore are excluded from segment results for Asset Retirement Obligations.”

all periods presented.

38


Income from operationsSegment incomefor each of the last three years is summarized and reconciled to net income in the following table:
               
(In millions) 2005 2004 2003
 
E&P            
 Domestic $1,564  $1,073  $1,155 
 International  1,424   623   425 
          
  E&P segment income  2,988   1,696   1,580 
RM&T  3,013   1,406   819 
IG  31   48   (3)
          
  Segment income  6,032   3,150   2,396 
Items not allocated to segments:            
 Administrative expenses  (367)  (307)  (227)
 
Loss on long-term U.K. gas contracts(a)
  (386)  (99)  (66)
 Gain on sale of minority interests in EGHoldings  23   –    –  
 
Impairment of certain oil and gas properties(b)
  –    (44)  –  
 
Corporate insurance adjustment(c)
  –    (32)  –  
 Gain (loss) on ownership change in MPC  –    2   (1)
 
Gain on asset dispositions(d)
  –    –    106 
 
Loss on dissolution of MKM Partners L.P.(e)
  –    –    (124)
          
  Income from operations $5,302  $2,670  $2,084 
 
(a)Amounts relate to long-term gas contracts in the U.K.table.

(In millions)

 2006
 2005
 2004
 

 
E&P          
 Domestic $873 $983 $674 
 International  1,130  904  416 
  
 
 
 
    E&P segment income  2,003  1,887  1,090 
RM&T  2,795  1,628  568 
IG  16  55  37 
  
 
 
 
    Segment income  4,814  3,570  1,695 
Items not allocated to segments, net of income taxes:          
 Corporate and other unallocated items  (212) (377) (327)
 Gain (loss) on long-term U.K. natural gas contracts(a)  232  (223) (57)
 Discontinued operations  277  45  (33)
 Gain on disposition of Syria interest  31  –    –   
 Deferred income taxes – tax legislation changes  21  15  –   
                                             – other adjustments(b)  93  –    –   
 Loss on early extinguishment of debt  (22) –    –   
 Gain on sale of minority interests in EGHoldings  –    21  –   
 Corporate insurance adjustment(c)  –    –    (17)
 Cumulative effect of change in accounting principle  –    (19) –   
  
 
 
 
    Net income $5,234 $3,032 $1,261 

 
(a)
Amounts relate to long-term natural gas contracts in the United Kingdom that are accounted for as derivative instruments and recorded at fair value. See “Critical Accounting Estimates – Fair Value Estimates” on page 34 for further discussion.
(b)Amount includes $32 million related to unproved properties and $12 million related to producing properties primarily due to unsuccessful developmental drilling activity in Russia.
(c)Insurance expense related to estimated future obligations to make certain insurance premium payments related to past loss experience.
(d)Amount represents a gain on the disposition of our interest in CLAM Petroleum B.V. and certain fields in the Big Horn Basin of Wyoming and SSA stores in Florida, North Carolina, South Carolina and Georgia.
(e)See Note 13 to the consolidated financial statements for a discussion of the dissolution of MKM Partners L.P.

39


Average Volumes, Selling Prices and recorded at fair value. See "Critical Accounting Estimates – Fair Value Estimates" on page 37 for further discussion.
(b)
Other Statistics
                
  2005 2004 2003
 
Net liquid hydrocarbon sales (mbpd)(a)(b)
            
 United States  76.4   81.2   106.5 
 Equity method investee  –    –    4.4 
          
  Total United States  76.4   81.2   110.9 
 Europe  36.3   39.8   41.5 
 Africa  51.7   32.5   27.1 
 Other International  26.6   15.6   10.0 
 Equity method investee  –    1.0   1.2 
  
Total International(c)
  114.6   88.9   79.8 
          
  Worldwide continuing operations  191.0   170.1   190.7 
 Discontinued operations  –    –    3.1 
          
WORLDWIDE  191.0   170.1   193.8 
Net natural gas sales (mmcfd)(b)(d)
            
 United States  577.6   631.2   731.6 
 Europe  262.0   291.8   285.9 
 Africa  92.4   76.4   65.9 
 Equity method investee  –    –    12.4 
          
  Total International  354.4   368.2   364.2 
  Worldwide continuing operations  932.0   999.4   1,095.8 
          
 Discontinued operations  –    –    74.1 
          
WORLDWIDE  932.0   999.4   1,169.9 
Total sales (mboepd)  346.3   336.7   388.8 
 
Average sales prices (excluding derivative gains and losses)            
 
Liquid hydrocarbons ($ per bbl)(a)
            
  United States $45.41  $32.76  $26.92 
  Equity method investee  –    –    29.45 
   Total United States  45.41   32.76   27.02 
  Europe  52.99   37.16   28.50 
  Africa  46.27   35.11   26.29 
  Other International  33.47   22.65   18.33 
  Equity method investee  –    21.10   13.72 
   Total International  45.43   33.68   26.24 
   Worldwide continuing operations  45.42   33.24   26.70 
  Discontinued operations  –    –    28.96 
WORLDWIDE $45.42  $33.24  $26.73 
 Natural gas ($ per mcf)            
  United States $6.42  $4.89  $4.53 
  Europe  5.70   4.13   3.35 
  Africa  0.25   0.25   0.25 
  Equity method investee  –    –    3.69 
   Total International  4.28   3.33   2.80 
   Worldwide continuing operations  5.61   4.31   3.95 
  Discontinued operations  –    –    5.43 
WORLDWIDE $5.61  $4.31  $4.05 
 
Refined products sales volumes (mbpd)(e)
  1,455   1,400   1,357 
Matching buy/sell volumes included in refined products volumes (mbpd)  77   71   64 
Refining and wholesale marketing margin (per gallon)(f)
 $0.1582  $0.0877  $0.0603 
 
(a)Includes crude oil, condensate and natural gas liquids.
(b)Amounts represent net sales after royalties, except for the U.K., Ireland and the Netherlands where amounts are before royalties for the applicable periods.
(c)Amounts represent equity tanker liftings and direct deliveries of liquid hydrocarbons. The amounts correspond with the basis for fiscal settlements with governments. Crude oil purchases, if any, from host governments are excluded.
(d)Includes natural gas acquired for injection and subsequent resale of 38.1, 19.3 and 23.4 mmcfd in 2005, 2004 and 2003, respectively. Effective July 1, 2005, the methodology for allocating sales volumes between natural gas produced from the Brae complex and third-party natural gas production was modified, resulting in an increase in volumes representing natural gas acquired for injection and subsequent resale.
(e)Total average daily volumes of refined product sales to wholesale, branded and retail (SSA) customers.
(f)Sales revenue less cost of refinery inputs, purchased products and manufacturing expenses, including depreciation.

deferred tax adjustments in 2006 represent a benefit recorded for cumulative income tax basis differences associated with prior periods.
(c)
Insurance expense in 2004 related to estimated future obligations to make certain insurance premium payments related to past loss experience.

40


DomesticUnited States E&P income decreased $110 million in 2006 from 2005. This was the result of a $182 million decline in pretax income, partially offset by a slight reduction in the effective income tax rate from 37 percent in 2005 to 36 percent in 2006. The decrease in pretax income was due to increases in variable production costs, exploration expenses, property impairments and depreciation, depletion and amortization. Exploration expenses in 2006 were $51 million higher than in 2005, with half of the increase related to a Gulf of Mexico exploratory dry well. As discussed above, U.S. E&P revenues were flat from 2005 to 2006.

        U.S. E&P income increased by $491$309 million in 2005 from 2004 following2004. This was the result of a decrease of $82$917 million in 2004 from 2003. Thepretax income increase in 2005 was primarily due to higher natural gas and liquid hydrocarbon prices partially offset by lower sales volumes.revenues as discussed above. The lower volumeseffective income tax rate was 37 percent in 2005 resulted primarily from weather-related downtime in the Gulf of Mexico and natural declines in field production rates. The decrease in 2004 was due to lower liquid hydrocarbon and natural gas volumes primarily resulting from natural field declines, weather-related downtime in the Gulf of Mexico and the sale of the Yates field in late 2003, partially offset by higher liquid hydrocarbon and natural gas prices. Derivative losses totaled $5 million in 2005, compared to $118 million in 2004 and $91 million in 2003.

both

43



years. Our cost of storm-related repairs as a result of 2005 hurricane activity in the Gulf of Mexico was not significant. Oursignificant and our Gulf of Mexico production hasquickly returned to pre-storm levels. In late September 2004, certain production platforms in the Gulf of Mexico were evacuated due to hurricane activity. All facilities were back on line by October 1, 2004 with the exception of the Petronius platform which came back on line in March 2005. As a result of the damage to the Petronius platform, we recorded expense of $11 million in 2004 representing repair costs incurred, partially offset by the net effects of the property damage insurance recoveries and the related retrospective insurance premiums. We recorded income of $53 million in 2005 and $34 million in 2004 for business interruption insurance recoveries.

     Our domestic average realized liquid hydrocarbons price excluding derivative activity was $45.41 per barrel (“bbl”)

International E&P income increased $226 million in 2006 from 2005, reflecting an increase in pretax income of $1.639 billion and an increase in the effective tax rate from 34 percent in 2005 compared to $32.76 per bbl62 percent in 2004 and $27.02 per bbl in 2003. Domestic average natural gas prices were $6.42 per thousand cubic feet (“mcf”) excluding derivative activity in 2005, compared with $4.89 per mcf in 2004 and $4.53 per mcf in 2003.

     Domestic net2006. The revenue increase discussed above, primarily related to higher liquid hydrocarbon sales volumes decreasedand prices in Libya, had the most significant impact on pretax income. Depreciation, depletion and amortization and other variable costs increased with increased production to 76 thousand barrels per day (“mbpd”)partially offset the revenue increase. Exploration expenses also increased $97 million in 2005, down 6 percent from 20042006 compared to 2005. Exploration expense related to dry wells and other write-offs was $68 million in 2006 and $44 million in 2005. Also included in 2006 exploration expense was $47 million for exiting the Cortland and Empire leases in Nova Scotia. The increase in the effective income tax rate was primarily as athe result of storm-related downtimethe income taxes related to our Libyan operations, where the statutory income tax rate is in excess of 90 percent, and the 2006 increase in the Gulf of Mexico and natural field declines in the Permian Basin. Domestic net natural gas sales volumes averaged 578 million cubic feet per day (“mmcfd”), down 8 percentU.K. supplemental corporation tax rate from 2004, primarily as a result of lower production in the Permian Basin and Camden Hills in the Gulf of Mexico due to natural field declines and downtime associated with Hurricane Ivan. Domestic net liquid hydrocarbon sales volumes decreased 2710 percent to 81 mbpd in 2004 from 2003 as a result of natural declines mainly in the Gulf of Mexico, hurricane damage to the Petronius platform and the sale of the Yates field in November 2003. Domestic net natural gas sales volumes decreased 14 percent to 631 mmcfd in 2004 from 2003 as a result of hurricane damage to the Petronius platform and natural declines in the Permian Basin and the Gulf of Mexico.
20 percent.

International E&P incomeincreased by $801$488 million in 2005 from 2004, and by $198 million in 2004 from 2003. Thereflecting an increase in 2005 waspretax income of $740 million and an effective income tax rate of 37 percent in both years. The revenue increase discussed above had the most significant impact on pretax income. Increases in production costs and depletion, depreciation and amortization related primarily the result of higher product prices and liquid hydrocarbon sales volumes, partially offset by higher production taxes in Russia, dry well expenses and lower natural gas sales volumes. The increase in 2004 was primarily due to higher liquid hydrocarbon and natural gas prices and volumes partially offset by higher derivative losses. Derivative losses totaled $386 million in 2005, compared to $51 million in 2004 and $19 million in 2003.

     Our international average realized liquid hydrocarbon price excluding derivative activity was $45.43 per bbl in 2005, compared with $33.68 per bbl in 2004 and $26.24 per bbl in 2003. International average gas prices were $4.28 per mcf excluding derivative activity in 2005, compared with $3.33 per mcf in 2004 and $2.80 per mcf in 2003.
     International net liquid hydrocarbon sales volumes increased to 115 mbpd in 2005, up 29 percent from 2004, as a result of increased production in Equatorial Guinea and Russia. International net natural gas sales volumes averaged 354 mmcfd in 2005, down 4 percent from 2004, primarily as a result of reduced U.K. spot gas sales. International net liquid hydrocarbon sales volumes increased 11 percent to 89 mbpd in 2004 from 2003 primarily due to increased production partially offset the benefit of higher revenue. Exploration expenses were also higher in Equatorial Guinea and a full year of production from Khanty Mansiysk Oil Corporation (“KMOC”) which was acquired in 2003. International net natural gas sales volumes averaged 368 mmcfd, up 1 percent from 2003 due to increased production from the condensate expansion project in Equatorial Guinea, offset by the disposition in 2003 of our interest in CLAM.
2005.

RM&T segment incomeincreased by $1.607$1.167 billion in 2006 from 2005 and $1.060 billion in 2005 from 20042004. Segment income in 2006 and 2005 benefited from the 38 percent minority interest in MPC that we acquired on June 30, 2005. Pre-tax income increased by $587$1.802 billion in 2006 from 2005 and $1.766 billion in 2005 from 2004. The pretax earnings reduction related to the minority interest was $376 million in 2004 from 2003.2005 and $539 million in 2004. The increases were primarily due to higherkey driver of the increase in RM&T pretax income in both years was our refining and wholesale marketing margins. The refining and wholesale marketinggross margin in 2005which averaged 15.822.88 cents per gallon versus a 2004 levelin 2006 compared to 15.82 cents in 2005 and 8.77 cents in 2004. The increase in the margin for 2006 reflected wider crack spreads, improved refined product sales realizations, the favorable effects of 8.8 centsour ethanol blending program and a 2003 level of 6.0 cents. Marginsincreased refinery throughputs. In 2005, the margin improved initially in 2005 due to wider sweet/sour crude oil differentials and more recently,later due to the temporary impact that Hurricanes Katrina and Rita had on refined product marginsprices and concerns about the adequacy of distillate supplies heading into that winter. Margins improved initially in 2004 due to the market’s concerns about refiners’ ability to supply the new Tier II low sulfur gasolines which were required effective January 1, 2004. We also benefited from wider sweet/sour crude differentials in 2004. We averaged 973,000 barrels of crude oil throughput per day in 2005, or 102 percent of average system capacity. We averaged 939,000 barrels of crude oil throughput per day in 2004 and 917,000 in 2003, representing 99 percent and 98 percent of average system capacity for those years.

41


     The portion of derivative losses included        Included in the refining and wholesale marketing gross margin were pretax gains of $400 million in 2006 and pretax losses of $238 million in 2005 compared toand $272 million in 2004 related to derivatives utilized primarily to manage price risk. These derivative gains and $158 million in 2003. Generally, losses on derivatives included in the refining and wholesale marketing margin are largely offset by gains and losses on the underlying physical transactions. Thesecommodity transactions related to these derivative positions. The change from derivative losses were primarily incurred to mitigatederivative gains reflects both improvements in the price riskrealized effects of certainour derivatives programs as well as unrealized effects as a result of marking open derivatives positions to market. See further discussion under "Item 7A. Quantitative and Qualitative Disclosures about Market Risk."

        We averaged 980 mbpd of crude oil and other feedstock purchases, to protect carrying valuesthroughput in 2006, or 101 percent of excess inventories and to protect crack spread values.

IG segment incomedecreased by $17 millionsystem capacity. We averaged 973 mbpd of crude oil throughput in 2005 from 2004, following an increase of $51 millionand 939 mbpd in 2004, from 2003. The decreaserepresenting 102 percent and 99 percent of system capacity for those years. Our capacity increased in 2005 was primarily due to increased income taxes for AMPCO as a result of the expirationDetroit refinery expansion from 74 to 100 mbpd.

        The following table includes certain key operating statistics for the RM&T segment for each of the last three years.

 
 2006
 2005
 2004

RM&T OPERATING STATISTICS         
Refining and wholesale marketing gross margin ($per gallon)(a) $0.2288 $0.1582 $0.0877
Refined products sales volumes (mbpd)(b)(c)  1,425  1,455  1,400
Matching buy/sell volumes included in refined products sales volumes (mbpd)(c)  24  77  71

(a)
Sales revenue less cost of refinery inputs, purchased products and manufacturing expenses, including depreciation.
(b)
Total average daily volumes of refined product sales to wholesale, branded and retail (SSA) customers.
(c)
On April 1, 2006, we changed our accounting for matching buy/sell transactions as a result of a tax holiday. Thenew accounting standard. This change resulted in lower refined product sales volumes for the remainder of 2006 than would have been reported under the previous accounting practices. See Note 2 to the consolidated financial statements.

44


IG segment income decreased $39 million in 2006 from 2005 compared to an increase of $18 million in 20042005 from 2004. In 2006, a $17 million pretax loss was primarily due to increased earningsrecognized as a result of the renegotiation of a technology agreement and income from our equity method investment in AMPCO was lower due to plant downtime during a planned turnaround and higher income from our Alaska LNG operations,subsequent compressor repair, partially offset by costs associated with ongoing development of certain integrated gas projects and lower margins from gas marketing activities, including recognized changeshigher realized methanol prices. The provision for income taxes also increased $15 million in the fair value of derivatives used to support those activities. Additionally, the 2003 results included an impairment charge of $22 million on an equity method investment and a loss of $17 million on the termination of two operating leases for tankers used in our Alaska LNG operations. The AMPCO methanol plant in Equatorial Guinea operated at a 98 percent on-stream factor in 2005 and a 95 percent on-stream factor in 2004, and posted index prices for methanol remained strong.

2006.


Management’sManagement's Discussion and Analysis of Financial Condition, Cash Flows and Liquidity

Financial Condition

     Both our acquisition of the minority interest in MPC and our re-entry to Libya discussed in Note 5 to the consolidated financial statements had a significant impact on our December 31, 2005 consolidated balance sheet. The MPC transaction closed June 30, 2005 and was accounted for under the purchase method of accounting. As a result, we established a new accounting basis for the tangible and identifiable intangible net assets of MPC to the extent of the 38 percent of MPC not previously owned by us, based on the estimated fair values of those net assets as of June 30, 2005. On December 29, 2005, we entered into an agreement with the National Oil Corporation of Libya to return to our oil and natural gas exploration and production operations in the Waha concessions in Libya. This transaction was also accounted for under the purchase method of accounting.
     Changes in the consolidated balance sheets from 2004 to 2005 were significantly impacted by the acquisitions noted above. For additional information on the effects of both of these transactions on our financial condition, see Note 5 to the consolidated financial statements. Other significant changes in the consolidated balance sheets are noted below.

        Net property, plant and equipment increased $3.201$1.642 billion from year-end 2004 due toin 2006 primarily as a result of the acquisitions noted above as well as the projects in Equatorial Guineacapital expenditures and the Alvheim development offshore Norway affecting International E&P, the Detroit refinery expansion affecting RM&T and the EG LNG plant affecting IG.additional capitalized asset retirement costs discussed below. Net property, plant and equipment for eachas of the end of the last two years is summarized in the following table:

            
(In millions) 2005 2004
 
E&P        
 Domestic $2,799  $2,644 
 International  4,737   3,530 
       
  Total E&P  7,536   6,174 
RM&T  6,113   4,842 
IG  1,157   621 
Corporate  205   173 
       
   Total $15,011  $11,810 
 
table.

(In millions)

 2006
 2005

E&P      
 Domestic $3,636 $2,811
 International  4,879  4,737
  
 
  Total E&P  8,515  7,548
RM&T  6,452  6,113
IG  1,378  1,145
Corporate  308  205
  
 
   Total $16,653 $15,011

        Asset retirement obligations increased $234$333 million in 2006 from year-end 20042005 primarily due to upward revisions of previous estimates related to increasing cost estimates, primarily in the U.K.United Kingdom, and Ireland, a changeto the accrual of obligations for new properties, primarily the Alvheim/Vilje development in Norway and the GabonLNG production sharing contract that created a retirement obligation and adoption of FIN No. 47 related to conditional asset retirement obligations on December 31, 2005.

facility in Equatorial Guinea.

Cash Flows

Net cash provided from operating activities (for continuing operations)totaled $5.488 billion in 2006, compared with $4.738 billion in 2005 compared withand $3.766 billion in 20042004. The $750 million increase in 2006 primarily reflects the impact of higher net income, partially offset by contributions of $635 million to our funded defined benefit pension plans and $2.765 billion in 2003.working capital changes. The 2005 increase mainly resulted from higher net income, partially offset by the effects of receivables which were transferred to Ashland at the Acquisition date. The 2004 increase was primarily the result

Net cash used in investing activities totaled $2.955 billion in 2006, compared with $3.127 billion in 2005 and $2.324 billion in 2004. Significant investing activities include capital expenditures, acquisitions of working capital changes.

businesses and asset disposals.

42


Capital expenditures by segment for continuing operations for each of the last three years are summarized in the following table:
                
(In millions) 2005 2004 2003
 
E&P            
 Domestic $637  $402  $344 
 International  823   542   629 
          
  Total E&P  1,460   944   973 
RM&T  841   794   789 
IG  572   490   131 
Corporate  17   19   16 
          
   Total $2,890  $2,247  $1,909 
 
     Capital expenditures in 2005 totaled $2.890 billion compared with $2.247 billion in 2004 and $1.909 billion in 2003.table.

(In millions)

 2006
 2005
 2004

E&P         
 Domestic $1,302 $638 $405
 International  867  728  435
  
 
 
  Total E&P  2,169  1,366  840
RM&T  916  841  794
IG  307  571  488
Corporate  41  18  19
  
 
 
   Total $3,433 $2,796 $2,141

        The $643$637 million increase in capital expenditures in 2006 over 2005 mainlyprimarily resulted from increased spending in the E&P segmentssegment and primarily relates to significant acreage acquisitions in the Bakken Shale in North Dakota and eastern Montana and the Piceance Basin of Colorado, as well as to continued work on the Alvheim/Vilje development offshore Norway and the Neptune development in the Gulf of Mexico. The $264 million decrease in integrated gas spending reflects the fact that the LNG production facility in Equatorial Guinea is nearing completion. The $655 million increase in 2005 capital expenditures over 2004 mainly resulted from increased spending related to the Alvheim development offshore Norway and the Equatorial Guinea LNG production facility.

45



Acquisitionsin the IG segment2006 primarily included cash payments of $718 million associated with the EG LNG plant. The increase of $338 millionour re-entry into Libya. Acquisitions in 2004 from 2003 mainly resulted from increased spending in the IG segment associated with the EG LNG plant.

Acquisitions2005 included cash payments of $506 million in 2005 for the acquisition of Ashland’sAshland's 38 percent ownership in MPC and $252 million in 2003 for the acquisition of KMOC.MPC. For further discussion of acquisitions, see Note 56 to the consolidated financial statements.
Cash from disposal

Disposal of assetswas and of discontinued operations totaled $966 million in 2006, compared with $131 million in 2005 compared withand $76 million in 2004 and $1.256 billion in 2003 which includes2004. Proceeds of $832 million from the disposal of discontinued operations.operations in 2006 related to the sale of our Russian exploration and production businesses in June 2006. In 2006, other disposals of assets included proceeds from the sale of 90 percent of our interest in Syrian natural gas fields, SSA stores and other domestic production and transportation assets. In 2005 and 2004, proceeds were primarily from the sale of various domestic producing properties and SSA stores. In 2003, proceeds were primarily from the disposition of our E&P properties in western Canada, the Yates field and gathering system, various SSA stores and other interests and producing properties.

Net cash used in financing activitiestotaled $2.581 billion in 2006, compared with $2.345 billion in 2005, compared withand net cash provided of $527 million in 20042004. Significant uses of cash in financing activities during 2006 included common stock repurchases under a previously announced plan, which is discussed under Liquidity and netCapital Resources, dividend payments, the repayment of our 6.65% notes that matured during 2006 and the early extinguishment of portions of our outstanding debt. The most significant use of cash used of $888 million in 2003. The change from 2004 to 2005 was primarily related to the repayment of $1.920 billion of debt assumed as a part of the Acquisition in 2005 andacquisition of Ashland's 38 percent of MPC. In 2004, cash provided from financing activities was primarily related to the issuance of 34,500,000 shares of common stock on March 31, 2004, resulting in net proceeds of $1.004 billion in 2004.billion. The change from 2004 to 2005 also included an increase in dividends paid and $272 million of distributions to the minority shareholder of MPC prior to the Acquisition, net of an increase in contributions from the minority shareholders of EGHoldings. The increase in 2004 was due to the net proceeds from the common stock issuance discussed above as well as the suspension of distributions to the minority shareholder of MPC in 2004. This was partially offset by an increase in dividends paid to stockholders.

Derivative Instruments

        See “Quantitative"Quantitative and Qualitative Disclosures about Market Risk”Risk" on page 53,56, for a discussion of derivative instruments and associated market risk.

Dividends to Stockholders

        Dividends of $1.22$1.53 per common share or $436$548 million were paid during 2005.2006. On January 29, 2006,2007, our Board of Directors declared a dividend of 33$0.40 cents per share on our common stock, payable March 10, 2006,12, 2007, to stockholders of record at the close of business on February 16, 2006.

21, 2007.

Liquidity and Capital Resources

        Our main sources of liquidity and capital resources are internally generated cash flow from operations, committed credit facilities and access to both the debt and equity capital markets. Our ability to access the debt capital market is supported by our investment grade credit ratings. Our senior unsecured debt is currently rated investment grade by Standard and Poor’sPoor's Corporation, Moody’sMoody's Investor Services, Inc. and Fitch Ratings with ratings of BBB+, Baa1, and BBB+. Because of the liquidity and capital resource alternatives available to us, including internally generated cash flow, we believe that our short-term and long-term liquidity is adequate to fund operations, including our capital spending programs, stock repurchase program, repayment of debt maturities for the years 2006, 2007 and 2008, and any amounts that may ultimately be paid in connection with contingencies.

     We have a committed

        During 2006, we entered into an amendment to our $1.5 billion five-year revolving credit agreement, expanding the size of the facility that terminates into $2.0 billion and extending the termination date from May 2009.2009 to May 2011. Concurrent with this amendment, the $500 million MPC revolving credit facility was terminated. At December 31, 2005,2006, there were no borrowings against this facility. At December 31, 2005,2006, we had no commercial

43


paper outstanding under our U.S. commercial paper program that is backed by the five-year revolving credit facility.
     MPC has

        During 2006 we entered into a committed $500loan agreement which allows borrowings of up to $525 million five-year revolvingfrom the Norwegian export credit facility with third-party financial institutions that terminatesagency based upon the amount of qualifying purchases by Marathon of goods and services from Norwegian suppliers. The loan agreement provides for either a fixed or floating interest rate option at the time of the initial drawdown. Should we elect to borrow under the agreement, the initial drawdown can only occur in May 2009. At December 31, 2005, there were no borrowings against this facility.

June 2007.

        As a condition of the closing agreements for the Acquisition, we are required to maintain MPC on a stand-alone basis financially for a two-year period.through June 30, 2007. During this period of time, capital contributions into MPC are prohibited and MPC is prohibited from incurring additional debt, except for borrowings under an existing intercompany loan facility to fund an expansion project at MPC’sMPC's Detroit refinery and in the event of limited extraordinary circumstances. MPC may only use its revolving credit facility for short-term working capital requirements in a manner consistent with past practices. There are no restrictions against MPC making intercompany loans or declaring dividends to its parent. We believe these facilitiesthat the

46



existing cash balances of MPC and cash provided from MPC’sits operations will be adequate to meet its stand-alone liquidity requirements.

requirements over the remainder of this two-year period.

        As of December 31, 2005,2006, there was $1.7 billion aggregate amount of common stock, preferred stock and other equity securities, debt securities, trust preferred securities or other securities, including securities convertible into or exchangeable for other equity or debt securities available to be issued under the $2.7 billion universal shelf registration statement filed with the Securities and Exchange Commission in 2002. On June 30, 2005, we issued $955 million of common stock to Ashland shareholders through a separate registration statement filed with the Securities and Exchange Commission which was declared effective May 20, 2005.

        Our cash-adjusteddebt-to-capital debt-to-capital ratio (total-debt-minus-cash to total-debt-plus-equity-minus-cash) was 11six percent at December 31, 2005,2006, compared to 811 percent at year-end 20042005 as shown below. This includes $543$519 million of debt that is serviced by United States Steel. We continually monitor our spending levels, market conditions and related interest rates to maintain what

(Dollars in millions)                  December 31

 2006
 2005
 

 
Long-term debt due within one year $471 $315 
Long-term debt  3,061  3,698 
  
 
 
 Total debt $3,532 $4,013 
Cash $2,585 $2,617 
Equity $14,607 $11,705 

 

Calculation:

 

 

 

 

 

 

 
Total debt $3,532 $4,013 
Minus cash  2,585  2,617 
  
 
 
 Total debt minus cash  947  1,396 
  
 
 
Total debt  3,532  4,013 
Plus equity  14,607�� 11,705 
Minus cash  2,585  2,617 
  
 
 
 Total debt plus equity minus cash $15,554 $13,101 
  
 
 
Cash-adjusted debt-to-capital ratio  6% 11%

 

        During 2006, we perceive to be reasonable debt levels.

          
  December 31 December 31
(Dollars in millions) 2005 2004
 
Long-term debt due within one year $315  $16 
Long-term debt  3,698   4,057 
       
 Total debt $4,013  $4,073 
Cash $2,617  $3,369 
Equity $11,705  $8,111 
 
Calculation:        
Total debt $4,013  $4,073 
Minus cash  2,617   3,369 
       
 Total debt minus cash  1,396   704 
       
Total debt  4,013   4,073 
Plus equity  11,705   8,111 
Minus cash  2,617   3,369 
       
 Total debt plus equity minus cash $13,101  $8,815 
       
Cash-adjusted debt-to-capital ratio  11%  8%
 
     On December 29, 2005, in conjunction with our partners in the former Oasis Group, we entered into an agreement with the National Oil Corporation of Libya to return to our oil and natural gas exploration and production operations in the Waha concessions in Libya. The re-entry terms include a25-year extension of the concessions to 2030 through 2034 and a payment of $520 million from us, which was made in January 2006. An additional payment estimated to be approximately $212 million is payable by us within one year of the agreement date.
     On January 29, 2006, our Board of Directors authorized the repurchase of up to $2 billionextinguished portions of our common stock overoutstanding debt with a periodtotal face value of two years. Such purchases will be made during this period as our financial condition and market conditions warrant. Any purchases under the program may be in either open market transactions, including block purchases, or in privately negotiated transactions.$162 million. The repurchase program does not include specificdebt was repurchased at a weighted average price targets, and is subjectequal to termination prior to completion.122 percent of face value. We will use cash on hand, cash generated from operations, or cash from available borrowingscontinue to acquire shares. Shares of stock repurchased under the program will be heldevaluate debt repurchase opportunities as treasury shares.
they arise.

44


     The table below provides aggregated information on our obligations to make future payments under existing contracts as of December 31, 2005:
Summary of Contractual Cash Obligations
                       
      2007- 2009- Later
(In millions) Total 2006 2008 2010 Years
 
Long-term debt (excludes interest)(a)(b)
 $3,874  $302  $850  $–   $2,722 
Sale-leaseback financing (includes imputed interest)(a)
  85   11   30   22   22 
Capital lease obligations(a)
  156   16   33   33   74 
Operating lease obligations(a)
  517   100   102   68   247 
Operating lease obligations under sublease(a)
  43   12   11   10   10 
Purchase obligations:                    
 
Crude oil, refinery feedstock and refined products contracts(c)
  10,771   10,660   111   –    –  
 Transportation and related contracts  1,027   209   271   150   397 
 Contracts to acquire property, plant and equipment  668   543   123   1   1 
 
LNG facility operating costs(d)
  192   13   25   25   129 
 
Service and materials contracts(e)
  185   71   45   38   31 
 
Unconditional purchase obligations(f)
  69   7   14   14   34 
 
Commitments for oil and gas exploration (non-capital)(g)
  20   20   –    –    –  
                
Total purchase obligations  12,932   11,523   589   228   592 
Other long-term liabilities reported in the consolidated balance sheet:                    
 
Employee benefit obligations(h)
  2,321   201   385   396   1,339 
                
Total contractual cash obligations(i)
 $19,928  $12,165  $2,000  $757  $5,006 
 
(a)Upon the Separation, United States Steel assumed certain debt and lease obligations. Such amounts are included in the above table because Marathon remains primarily liable.
(b)We anticipate cash payments for interest of $255 million for 2006, $432 million for 2007-2008, $385 million for 2009-2010 and $1.658 billion for the remaining years for a total of $2.730 billion.
(c)The majority of contractual obligations to purchase crude oil, refinery feedstock and refined products as of December 31, 2005 relate to contracts to be satisfied within the first 180 days of 2006.
(d)We have acquired the right to deliver 58 bcf of natural gas per year to the Elba Island LNG re-gasification terminal. The agreement’s primary term ends in 2021. Pursuant to this agreement, we are also committed to pay for a portion of the operating costs of the LNG re-gasification terminal.
(e)Service and materials contracts include contracts to purchase services such as utilities, supplies and various other maintenance and operating services.
(f)We are a party to a long-term transportation services agreement with Alliance Pipeline. This agreement is used by Alliance Pipeline to secure its financing. This arrangement represents an indirect guarantee of indebtedness. Therefore, this amount has also been disclosed as a guarantee. See Note 28 to the consolidated financial statements for a complete discussion of our guarantee.
(g)Commitments for oil and gas exploration (non-capital) include estimated costs related to contractually obligated exploratory work programs that are expensed immediately, such as geological and geophysical costs.
(h)We have employee benefit obligations consisting of pensions and other postretirement benefits including medical and life insurance. We have estimated projected funding requirements through 2014.
(i)Includes $625 million of contractual cash obligations that have been assumed by United States Steel. For additional information, see “Management’s Discussion and Analysis of Financial Condition, Cash Flows and Liquidity – Obligations Associated with the Separation of United States Steel – Summary of Contractual Cash Obligations Assumed by United States Steel” on page 47.
     Contractual cash obligations for which the ultimate settlement amounts are not fixed and determinable have been excluded from the above table. These include derivative contracts that are sensitive to future changes in commodity prices and other factors.
     Note 23 to the consolidated financial statements includes detailed information for the three years ended December 31, 2005, on the funded status for our pension plans as of December 31, 2005 and 2004. Under prescribed regulatory minimum funding requirements, we have satisfied the minimum funding obligations related to the pension plans and therefore no contributions are required from us. However, we plan to make discretionary cash contributions of between $155 million and $345 million in 2006.

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        Our opinions concerning liquidity and our ability to avail ourselves in the future of the financing options mentioned in the above forward-looking statements are based on currently available information. If this information proves to be inaccurate, future availability of financing may be adversely affected. Factors that affect the availability of financing include our performance (as measured by various factors including cash provided from operating activities), the state of worldwide debt and equity markets, investor perceptions and expectations of past and future performance, the global financial climate, and, in particular, with respect to borrowings, the levels of our outstanding debt and credit ratings by rating agencies.

Stock Repurchase Program

        In January 2006, we announced a $2 billion share repurchase program. In January 2007, our Board of Directors authorized the extension of this share repurchase program by an additional $500 million. As of February 21, 2007, we had repurchased 24.2 million common shares at a cost of $2 billion. We anticipate completing the additional $500 million in share repurchases during the first half of 2007. Purchases under the program may be in either open market transactions, including block purchases, or in privately negotiated transactions. We will use cash on hand, cash generated from operations or cash from available borrowings to acquire shares. This program may be changed based upon our financial condition or changes in market conditions and is subject to termination prior to completion.

        The forward-looking statements about our common stock repurchase program are based on current expectations, estimates and projections and are not guarantees of future performance. Actual results may differ materially from these expectations, estimates and projections and are subject to certain risks, uncertainties and other factors, some of which are beyond our control and are difficult to predict. Some factors that could cause actual results to differ materially are changes in prices of and demand for crude oil, natural gas and refined products, actions of competitors, disruptions or interruptions of our production or refining operations due to unforeseen hazards such as weather conditions, acts of war or terrorist acts and the governmental or military response, thereto, and other operating and economic considerations.

Off-Balance Sheet Arrangements

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Contractual Cash Obligations

        The table below provides aggregated information on our obligations to make future payments under existing contracts as of December 31, 2006.


Summary of Contractual Cash Obligations

(In millions)

 Total
 2007
 2008-
2009

 2010-
2011

 Later
Years


Long-term debt (excludes interest)(a)(b) $3,398 $450 $400 $143 $2,405
Sale-leaseback financing (includes imputed interest)(a)  75  20  22  22  11
Capital lease obligations(a)  141  16  33  33  59
Operating lease obligations(a)  851  154  286  158  253
Operating lease obligations under sublease(a)  32  5  11  11  5
Purchase obligations:               
 Crude oil, refinery feedstock, refined product and ethanol contracts(c)  14,419  12,588  852  655  324
 Transportation and related contracts  1,445  515  323  201  406
 Contracts to acquire property, plant and equipment  1,703  935  719  37  12
 LNG terminal operating costs(d)  178  13  24  25  116
 Service and materials contracts(e)  602  210  231  81  80
 Unconditional purchase obligations(f)  62  7  14  14  27
 Commitments for oil and gas exploration (non-capital)(g)  100  57  31  2  10
  
 
 
 
 
   Total purchase obligations  18,509  14,325  2,194  1,015  975
Other long-term liabilities reported in the consolidated balance sheet:               
 Defined benefit postretirement plan obligations(h)  1,627  97  164  276  1,090
  
 
 
 
 
Total contractual cash obligations(i) $24,633 $15,067 $3,110 $1,658 $4,798

(a)
Upon the Separation, United States Steel assumed certain debt and lease obligations. Such amounts are included in the above table because Marathon remains primarily liable.
(b)
We anticipate cash payments for interest of $227 million for 2007, $364 million for 2008-2009, $357 million for 2010-2011 and $1.387 billion for the remaining years for a total of $2.335 billion.
(c)
The majority of these contractual obligations as of December 31, 2006 relate to contracts to be satisfied within the first 180 days of 2007. These contracts include variable price arrangements and some contracts are accounted for as nontraditional derivatives.
(d)
We have acquired the right to deliver 58 bcf of natural gas per year to the Elba Island LNG re-gasification terminal. The agreement's primary term ends in 2021. Pursuant to this agreement, we are also committed to pay for a portion of the operating costs of the terminal.
(e)
Service and materials contracts include contracts to purchase services such as utilities, supplies and various other maintenance and operating services.
(f)
We are a party to a long-term transportation services agreement with Alliance Pipeline. This agreement is used by Alliance Pipeline to secure its financing. This arrangement represents an indirect guarantee of indebtedness. Therefore, this amount has also been disclosed as a guarantee. See Note 30 to the consolidated financial statements for a complete discussion of our guarantee.
(g)
Commitments for oil and gas exploration (non-capital) include estimated costs related to contractually obligated exploratory work programs that are expensed immediately, such as geological and geophysical costs.
(h)
We have obligations consisting of pensions and other postretirement benefits including medical and life insurance. We have estimated projected funding requirements through 2016.
(i)
Includes $581 million of contractual cash obligations that have been assumed by United States Steel. For additional information, see "Management's Discussion and Analysis of Financial Condition, Cash Flows and Liquidity – Obligations Associated with the Separation of United States Steel – Summary of Contractual Cash Obligations Assumed by United States Steel" on page 49.

Off-Balance Sheet Arrangements

        Off-balance sheet arrangements comprise those arrangements that may potentially impact our liquidity, capital resources and results of operations, even though such arrangements are not recorded as liabilities under generally accepted accounting principles. Although off-balance sheet arrangements serve a variety of our business purposes, we are not dependent on these arrangements to maintain our liquidity and capital resources; and we are not aware of any circumstances that are reasonably likely to cause the off-balance sheet arrangements to have a material adverse effect on liquidity and capital resources.

        We have provided various forms of guarantees to unconsolidated affiliates, United States Steel and certain lease contracts.others. These arrangements are described in Note 2830 to the consolidated financial statements.

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We are a party to an agreement that would require us to purchase, under certain circumstances, the interest in Pilot Travel Centers LLC (“PTC”("PTC") not currently owned. This put/call agreement is described in Note 2830 to the consolidated financial statements.

Nonrecourse Indebtedness of Investees

Nonrecourse Indebtedness of Investees

        Certain of our investees have incurred indebtedness that we do not support through guarantees or otherwise. If we were obligated to share in this debt on a pro rata ownership basis, our share would have been approximately $308$340 million as of December 31, 2005.2006. Of this amount, $183$217 million relates to PTC. If any of these investees default, we have no obligation to support the debt. Our partner in PTC has guaranteed $125$75 million of the total PTC debt.

Obligations Associated with the Separation of United States Steel

Obligations Associated with the Separation of United States Steel

        On December 31, 2001, we disposed of our steel business through a tax-free distribution of the common stock of our wholly owned subsidiary, United States Steel, to holders of our USX – U.S.U. S. Steel Group class of common stock in exchange for all outstanding shares of Steel Stock on a one-for-one basis.

        We remain obligated (primarily or contingently) for certain debt and other financial arrangements for which United States Steel has assumed responsibility for repayment under the terms of the Separation. United States Steel’sSteel's obligations to Marathon are general unsecured obligations that rank equal to United States Steel’sSteel's accounts payable and other general unsecured obligations. If United States Steel fails to satisfy these obligations, we would become responsible for repayment. Under the Financial Matters Agreement, United States Steel has all of the existing contractual rights under the leases assumed from Marathon, including all rights related to purchase options, prepayments or the grant or release of security interests. However, United States Steel has no right to increase amounts due under or lengthen the term of any of the assumed leases, other than extensions set forth in the terms of the assumed leases.

        As of December 31, 2005,2006, we have identified the following obligations totaling $597$564 million that have been assumed by United States Steel:

• $428 million of industrial revenue bonds related to environmental improvement projects for current and former United States Steel facilities, with maturities ranging from 2009 through 2033. Accrued interest payable on these bonds was $9 million at December 31, 2005.
• $66 million of sale-leaseback financing under a lease for equipment at United States Steel’s Fairfield Works, with a term extending to 2012, subject to extensions. There was no accrued interest payable on this financing at December 31, 2005.

46


• $49 million of obligations under a lease for equipment at United States Steel’s Clairton cokemaking facility, with a term extending to 2012. There was no accrued interest payable on this financing at December 31, 2005.
• $45 million of operating lease obligations, of which $37 million was in turn assumed by purchasers of major equipment used in plants and operations divested by United States Steel.
• A guarantee of all obligations of United States Steel as general partner of Clairton 1314B Partnership, L.P. to the limited partners. United States Steel has reported that it currently has no unpaid outstanding obligations to the limited partners. For further discussion of the Clairton 1314B guarantee, see Note 3 to the consolidated financial statements.
        Of the total $597$564 million, obligations of $552$530 million and corresponding receivables from United States Steel were recorded on our consolidated balance sheet as of December 31, 20052006 (current portion – $20$32 million; long-term portion – $532$498 million). The remaining $45$34 million was related to off-balance sheet arrangements and contingent liabilities of United States Steel.

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        The table below provides aggregated information on the portion of our obligations to make future payments under existing contracts that have been assumed by United States Steel as of December 31, 2005:

2006:


Summary of Contractual Cash Obligations Assumed by United States Steel

                      
      2007- 2009- Later
(In millions) Total 2006 2008 2010 Years
 
 
Long-term debt(a)
 $428  $–   $–   $–   $428 
 Sale-leaseback financing (includes imputed interest)  85   11   30   22   22 
 Capital lease obligations  67   10   19   19   19 
 Operating lease obligations  8   5   3   –    –  
 Operating lease obligations under sublease  37   5   11   10   11 
                
Total contractual obligations assumed by United States Steel
 $625  $31  $63  $51  $480 
 
(a)We anticipate cash payments for interest of $24 million for 2006, $47 million for 2007-2008, $47 million for 2009-2010 and $272

(In millions)

 Total
 2007
 2008-
2009

 2010-
2011

 Later
Years


Contractual obligations assumed by United States Steel               
 Long-term debt(a) $415 $–   $–   $–   $415
 Sale-leaseback financing (includes imputed interest)  75  20  22  22  11
 Capital lease obligations  58  10  19  19  10
 Operating lease obligations  3  3  –    –    –  
 Operating lease obligations under sublease  30  5  10  10  5
  
 
 
 
 
Total contractual obligations assumed by United States Steel $581 $38 $51 $51 $441

(a)
We anticipate cash payments for interest of $23 million for 2007, $46 million for 2008-2009, $45 million for 2010-2011 and $239 million for the later years to be assumed by United States Steel.
     Each of Marathon and United States Steel, as members of the same consolidated tax reporting group during taxable periods ended on or before December 31, 2001, is jointly and severally liable for the federal income tax liability of the entire consolidated tax reporting group for those periods.Steel.

        Marathon and United States Steel have entered into a tax sharing agreement that allocates tax liabilities relating to taxable periods ended on or before December 31, 2001. The agreement includes indemnification provisions to address the possibility that the taxing authorities may seek to collect a tax liability from one party where the tax sharing agreement allocates that liability to the other party. In 2006 and 2005, in accordance with the terms of the tax sharing agreement, we paid $35 million and $6 million to United States Steel in connection with the settlement with the Internal Revenue Service of the consolidated federal income tax returns of USX Corporation for the years 1995 through 1997.

2001. The final payment of $13 million to United States Steel related to U.S. federal income tax returns under the tax sharing agreement was made in January 2007.

        United States Steel reported in its Form 10-K for the year ended December 31, 2005,2006, that it has significant restrictive covenants related to its indebtedness including cross-default and cross-acceleration clauses on selected debt that could have an adverse effect on its financial position and liquidity. However, United States Steel management believes that its liquidity will be adequate to satisfy its obligations for the foreseeable future.

Transactions with Related Parties

Transactions with Related Parties

        We own a 63 percent working interest in the Alba field offshore EG.Equatorial Guinea. We own a 52 percent interest in an onshore LPG processing plant in EG through an equity method investee, Alba Plant LLC. Additionally, we own a 45 percent interest in an onshore methanol production plant through AMPCO, an equity method investee. We sell our marketed natural gas from the Alba field to Alba Plant LLC and AMPCO. AMPCO uses the natural gas to manufacture methanol and sells the methanol through another equity method investee, AMPCO Marketing LLC.

        Sales to our 50 percent equity method investee, PTC, which consists primarily of refined petroleum products, accounted for less than two percent or less of our total sales revenue for 2006, 2005 2004 and 2003.2004. PTC is the largest travel center network in the United States and operates approximately 260269 travel centers nationwide. We also sellin the United States and Canada. Prior to the Acquisition on June 30, 2005, Ashland was a related party as a result of its 38 percent minority interest in MPC. During that time, we sold refined petroleum products consisting mainly of petrochemicals, base lube oils and asphalt to Ashland which owned a 38 percent interest in MPC prior to the Acquisition.Ashland. Our sales to Ashland accounted for less than one percent of our total sales revenue for 2005 2004 and 2003.2004. We believe that these transactions were conducted under terms comparable to those with unrelated parties.

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        Marathon holds a 60 percent economic interest, GEPetrolSONAGAS holds a 25 percent economic interest, Mitsui holds an 8.5 percent economic interest and Marubeni holds a 6.5 percent economic interest in EGHoldings. As of December 31, 2005,2006, total expenditures of $1.116$1.363 billion, including $1.066$1.300 billion of capital expenditures, related to the Equatorial Guinea LNG projectproduction facility have been incurred. Cash of $57$234 million held in escrow to fund future contributions from GEPetrolSONAGAS to EGHoldings is classified as restricted cash and is included in investments and long-term receivables. Payablesreceivables as of December 31, 2006. Our current receivables from and payables to related parties include $57the interest holders in EGHoldings are $13 million and $232 million as of December 31, 2006, including a payable to GEPetrol.
SONAGAS of $229 million.


Management’sManagement's Discussion and Analysis of Environmental Matters, Litigation and Contingencies

        We have incurred and will continue to incur substantial capital, operating and maintenance, and remediation expenditures as a result of environmental laws and regulations. If these expenditures, as with all costs, are not ultimately recoveredreflected in the prices of our products and services, our operating results will be adversely affected. We believe that substantially all of our competitors must comply with similar environmental laws and regulations.

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However, the specific impact on each competitor may vary depending on a number of factors, including the age and location of its operating facilities, marketing areas, production processes and whether it is also engaged in the petrochemical business or the marine transportation of crude oil and refined products.

        Our environmental expenditures for each of the last three years were(a):

               
(In millions) 2005 2004 2003
 
Capital $390  $433  $331 
Compliance            
 Operating & maintenance  250   215   243 
 
Remediation(b)
  25   32   44 
          
  Total $665  $680  $618 
 
(a)Amounts are determined based on American Petroleum Institute survey guidelines.
(b)These amounts include spending charged against remediation reserves, where permissible, but exclude non-cash provisions recorded for environmental remediation.

(In millions)

 2006
 2005
 2004

Capital $166 $390 $433
Compliance         
 Operating & maintenance  319  250  215
 Remediation(b)  20  25  32
  
 
 
   Total $505 $665 $680

(a)
Amounts are determined based on American Petroleum Institute survey guidelines.
(b)
These amounts include spending charged against remediation reserves, where permissible, but exclude non-cash provisions recorded for environmental remediation.

        Our environmental capital expenditures accounted for 135 percent of total capital expenditures for continuing operations in 2006, 14 percent in 2005 19and 20 percent in 2004 and 17 percent in 2003.

2004.

        We accrue for environmental remediation activities when the responsibility to remediate is probable and the amount of associated costs can be reasonably estimated. As environmental remediation matters proceed toward ultimate resolution or as additional remediation obligations arise, charges in excess of those previously accrued may be required.

        New or expanded environmental requirements, which could increase our environmental costs, may arise in the future. We comply with all legal requirements regarding the environment, but since not all of them are fixed or presently determinable (even under existing legislation) and may be affected by future legislation or regulations, it is not possible to predict all of the ultimate costs of compliance, including remediation costs that may be incurred and penalties that may be imposed.

        Our environmental capital expenditures are expected to be approximately $218$159 million or 78 percent of capital expenditures in 2006.2007. Predictions beyond 20062007 can only be broad-based estimates, which have varied, and will continue to vary, due to the ongoing evolution of specific regulatory requirements, the possible imposition of more stringent requirements and the availability of new technologies, among other matters. Based on currently identified projects, we anticipate that environmental capital expenditures will be approximately $147$277 million in 2007;2008; however, actual expenditures may vary as the number and scope of environmental projects are revised as a result of improved technology or changes in regulatory requirements and could increase if additional projects are identified or additional requirements are imposed.

        Of particular significance to our refining operations arewere U.S. EPA regulations that requirerequired reduced sulfur levels starting in 2004 for gasoline and in 2006 for diesel fuel. Our combined capital costs to achieveWe achieved compliance with these rules are expectedregulations and began production of ultra-low sulfur diesel fuel for on-road use prior to approximate $900the June 1, 2006 deadline. The cost of achieving compliance with these regulations was approximately $850 million. We will also be spending approximately $250 million from 2006 through 2010 to produce ultra-low sulfur diesel fuel for off-road use. Further, we estimate that we will spend approximately $400 million over thea four-year period between 2002 and 2006, which includes costs that could be incurred as part of other refinery upgrade projects. Costs incurred through December 31, 2005, were approximately $825 million,beginning in 2008 to comply with the remainder expectedMobile Source Air Toxics II regulations relating to be incurred in 2006.benzene. This is a forward-looking statement. Some factors (among others) that could potentially affect gasoline and diesel fuel compliance costs include completionpreliminary estimate as the Mobile Source Air Toxics II regulations should be finalized in the first half of construction andstart-up activities.

2007.

        During 2001, MPC entered into a New Source Review consent decree and settlement of alleged CAAClean Air Act and other violations with the EPA covering all of MPC’sits refineries. The settlement committed MPC to specific control technologies and implementation schedules for environmental expenditures and improvements to MPC’sits refineries over approximately an eight-year period. The total one-time expenditures for these environmental projects are

48


approximately $420 million over the eight-year period, with about $265 million incurred through December 31, 2005. The impact of the settlement on ongoing operating expenses is expected to be immaterial. In addition, MPC has nearly completedbeen working on certain agreed upon supplemental environmental projects as part of this settlement of an enforcement action for alleged CAA violations at a costand these have been substantially completed.

        The oil industry across the U.K. continental shelf is making reductions in the amount of $9 million. We believe this settlement will provide MPC with increased permitting and operating flexibility while achieving significant emission reductions. In 2005, MPC entered into two amendments of the consent decree which captured all revisionsoil in its produced water discharges pursuant to the decree agreedDepartment of Trade and Industry initiative under the Oil Pollution Prevention and Control Regulations ("OSPAR") of 2005. In compliance with these regulations, we have almost completed our OSPAR project for the Brae field to withmake the EPA since 2001. The revisions related to userequired reductions of additives and control technologies along with schedule adjustments and other changes. Theoil in its produced water discharges. Our share of capital costs of these consent decree revisions are immaterial and are included infor the cost estimates provided in this paragraph.

project is $7 million.

        For information on legal proceedings related to environmental matters, see “Item"Item 3. Legal Proceedings.

"

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Outlook

Capital, Investment and Exploration Budget

        We approved a capital, investment and exploration budget of $3.4$4.242 billion for 2006,2007, which includes budgeted capital expenditures of $3.2$3.886 billion. This represents a 1316 percent increase over 20052006 actual spending. The primary focus of the 20062007 budget is to find additional oil and natural gas reserves, develop existing fields, strengthen RM&T assets and continue implementation of the integrated gas strategy. The budget includes worldwide production capital spending of $1.357$1.429 billion primarily in the United States, Norway, Russia, Equatorial GuineaLibya and Ireland. The worldwide exploration budget of $588$802 million includes plans to drill 1914 to 17 significant exploration or appraisal wells. Other activities will focus primarily on projects primarilyareas within or adjacent to our onshore producing properties in the United States. The budget includes $886 million$1.464 billion for RM&T, primarily for refining projects including the 180 mbpd Garyville refinery expansion project and the FEED for a potential Detroit refinery heavy oil upgrading project which would allow us to process increased volumes of Canadian oil sands production. The RM&T budget also includes increased investments targeting value-added projects primarily aimedin transportation and logistics, a strategically important area of the business, including the expansion of our ethanol blending capabilities at de-bottlenecking various refining components to increase throughput capacity, as well as investments necessary to meet revised EPA National Ambient Air Quality Standards, best achievable control technology and Tier II Clean Fuels regulations. Also includedterminals in the budget for RM&T is planned spending for the FEED work being undertaken for the potential 180,000 bpd Garyville, Louisiana refinery expansion project.Midwest and Southeast. The IGintegrated gas budget of $341$331 million is primarily for the ongoing constructioncompletion of the EG LNG plant.processing facility in Equatorial Guinea, as well as FEED expenditures associated with a potential expansion of that facility. The remaining $210$216 million balance is designated for capitalized interest and corporate activities. This budget does not include the 2006 cash payments related to our re-entry to Libya, estimated to be $732 million.

Exploration and Production

     Our eight

        The seven announced discoveries in 20052006 (six in deepwater Angola and one in Norway) resulted from our balanced exploration strategy which places an emphasis on near-term production opportunities, while retaining an appropriate exposure to longer-term options. Major exploration activities, which are currently underway or under evaluation, include those in:

• Offshore Angola, where development options for the northeast area of Block 31, which includes the Plutao, Saturno, Marte and Venus discoveries, are currently being evaluated. Also on Block 31 during 2005, the announcement of five discoveries, Ceres, Palas, Juno, Astraea and Hebe, in the southeastern part of the block reinforce the likelihood of a second development area. The Urano well was started in December 2005 and drilling is in progress. We own a 10 percent interest in Block 31. We have secured rig capacity for and plan to participate in five exploration wells during 2006.
• On Angola Block 32, in which we own a 30 percent interest, three discoveries were announced, Gindungo, Canela and Gengibre. We also participated in a well on the Cola prospect that encountered hydrocarbons, but additional drilling will be required to determine commerciality. Finally, we announced a successful appraisal of the Gengibre discovery and the Mostarda well has reached total depth. These results will be announced following government approval. We have secured rig capacity for and plan to participate in six exploration wells during 2006.
• Equatorial Guinea, where we are evaluating development scenarios for the Deep Luba and Gardenia discoveries on the Alba Block, one of which includes production through the Alba field infrastructure and the future LNG facility under construction on Bioko Island. We own a 63 percent interest in the Alba Block and serve as operator.
• Norway, where we acquired four new Norwegian exploration licenses (three operated) in the December 2004 APA License Round. We now own interests in 16 licenses in the Norwegian sector of the North Sea and plan to drill one to two exploration wells during 2006.
• Gulf of Mexico, where we plan to participate in one to four wells during 2006.
those:

49


        During 2005,2006, we continued to make progress in advancing key development projects that will help serve as the basis for our production growth profile in the coming years. Major development and production activities currently underway or under evaluation include those in:
• Libya, where we re-entered the Waha concessions at the end of 2005 and have extended the licenses for an additional 25 years. In 2006 we will do more detailed analysis of work to be completed to maximize the potential of this major asset which currently produces 350,000 bpd gross and we expect to contribute 40,000 to 45,000 bpd net to Marathon duringthose:

    in Libya, where we re-entered the Waha concessions at the end of 2005 and achieved first production in January 2006. We continue to work with our partners to maximize the potential of this major asset. We own a 16.33 percent outside-operated interest in the approximately 13 million acre Waha concessions;

    in Norway, where our Alvheim/Vilje development will consist of a floating production, storage and offloading vessel with subsea infrastructure for five drill centers and associated flow lines. Construction on the project is nearly complete and commissioning has commenced. First production is expected during the second quarter 2007, at which time four wells will be available, and drilling activities will continue into 2008. A peak net production rate of 75 mboepd is expected in early 2008. The Alvheim development includes the Kneler, Boa

52


      and Kameleon fields in which we own a 65 percent interest and serve as operator. We own a 47 percent outside-operated interest in the nearby Vilje discovery. Also, plans for development of the Volund discovery as a 16.33 percent interest in the approximately 13 million acre Waha concessions.

• Norway, where our Alvheim development will consist of a floating production, storage and offloading (“FPSO”) vessel with subsea infrastructure for five drill centers and associated flow lines. At year-end 2005 the project was 43 percent complete with production expected to start during the first quarter 2007. The Alvheim development includes the Kneler, Boa and Kameleon fields in which we own a 65 percent interest and serve as operator. A development plan for the nearby Vilje discovery, in which we own a 47 percent interest, was approved by the Norwegian Government in 2005. The combined Alvheim/ Vilje developments are expected to ramp up production in the first quarter of 2007 to more than 50,000 net boepd. Also, results for the Volund well (formerly Hamsun) are being analyzed and development scenarios are being examined, including a possible tie-back to the Alvheim development. We own a 65 percent interest in Volund and serve as operator.
• Gulf of Mexico, where the Neptune development was sanctioned during 2005 and which is on track for first production in late 2007 or early 2008.
• Equatorial Guinea, where we completed our LPG expansion project and ramped up liquids production to approximately 86,000 gross bpd (49,000 bpd net to Marathon) by the end of 2005. We continue to exceed our initial liquids production projection, as gross production available for sale in January 2006 was approximately 90,000 bpd (51,000 bpd net to Marathon).
• Russia, where our successful drilling program in East Kamennoye took our production to greater than 30,000 net bpd at year end, more than double the production level when we acquired the assets in 2003.
     In January 2006, we began to experience pipeline operational problems related to the increasing waterAlvheim development were approved by the Norwegian Government in early 2007. First production associated withis expected from Volund in the natural gas production from the Camden Hills field second quarter of 2009. We own a 65 percent interest in Volund and serve as operator;

in the Gulf of Mexico. If these issues cannot be resolved,Mexico, where the Neptune development is on target for first production by early 2008. We own a 30 percent outside-operated interest in Neptune;

in Ireland, where the Corrib natural gas development project has re-commenced and we may needexpect first production in 2009. We own a 19 percent outside-operated interest in Corrib;

in the Piceance Basin where we plan to impair somedrill approximately 700 wells over the next ten years, with first production expected in late 2007; and

in the Bakken Shale where we plan to drill approximately 300 locations over the next five years.

        We estimate that our 2007 production available for sale will average approximately 390 to 425 mboepd, excluding the impact of acquisitions and dispositions. With the developments we have under construction, we estimate our production available for sale will grow to 465 to 520 mboepd by 2010, excluding acquisitions and dispositions. Projected liquid hydrocarbon and natural gas production available for sale is based on a number of assumptions, including (among others) pricing, supply and demand for petroleum products, the amount of capital available for exploration and development, regulatory constraints, production decline rates of mature fields, timing of commencing production from new wells, drilling rig availability, inability or alldelay in obtaining necessary government and third-party approvals and permits, unforeseen hazards such as weather conditions, acts of the carrying value of the fieldwar or terrorist acts and the associated Canyon Express pipeline. At December 31, 2005, the combined carrying value of those assets approximated $20 million.

government or military response, and other geological, operating and economic considerations. These assumptions may prove to be inaccurate.

        In 2006, we issued a request for proposals to engage interested parties in a process that could lead to a Canadian oil sands venture. This process is intended to explore various commercial arrangements under which we would provide heavy Canadian oil sands crude oil processing capacity in exchange for an equity interest in a Canadian oil sands project through a joint venture, or other alternative business arrangements that potential partners may choose to propose.

        The above discussion includes forward-looking statements with respect to anticipated future exploratory and development drilling, the timing and levelspossibility of our worldwide liquid hydrocarbon and natural gas production, future exploration and drilling activity, possible development ofdeveloping Blocks 31 and 32 offshore Angola, the timing of production from the Neptune development, the Piceance Basin, the combined Alvheim/Vilje development, the Volund field and estimated levels of production in Libya.the Corrib project. Some factors thatwhich could potentially affect thisthese forward-looking informationstatements include pricing, supply and demand for petroleum products, the amount of capital available for exploration and development, occurrence of acquisitions/dispositions of oil and gas properties, regulatory constraints, timing of commencing production from new wells, drilling rig availability, unforeseen hazards such as weather conditions, acts of war or terrorist acts and the governmental or military response, thereto, and other geological, operating and economic considerations. Except for the Alvheim/Vilje and Volund developments, the foregoing forward-looking statements may be further affected by the inability to or delay in obtaining necessary government and third-party approvals and permits. The estimated levels of productionpossible developments in Libya and possible development of Blocks 31 and 32 offshore Angola could further be affected by presently known data concerning size and character of reservoirs, economic recoverability, future drilling success and production experience. The above discussion also contains forward-looking statements concerning a potential Canadian oil sands venture. Factors that could affect the formation of a Canadian oil sands venture include unforeseen difficulty in negotiation of definitive agreements, results of front-end engineering and design work, inability or delay in obtaining necessary government and third-party approvals, continued favorable investment climate, and other geological, operating and economic considerations. The foregoing factors (among others) could cause actual results to differ materially from those set forth in the forward-looking statements.

Refining, Marketing and Transportation

        Throughout 2005,2006, we remained focused on our strategy of leveraging refining and marketing investments in core markets, as well as expanding and enhancing our asset base while controlling costs. The record refinery throughput performance was achieved even though the Garyville, Louisiana and Texas City, Texas refineries were shut down briefly due to Hurricanes Katrina and Rita. Based on our current plans, we expect ourOur 2006 average daily crude oil throughput to exceed thatexceeded the record throughput achieved in 2005.

     The Detroit refinery expansion was completed in the fourth quarter

        In 2006, our Board of 2005. This project increased the refinery’s crude processing capacity from 74,000 bpd to 100,000 bpd as well as enabled the refinery to produce new clean fuels and further control regulated air emissions. The refinery ramped up to full capacity of 100,000 bpd in mid-November.

     We plan to evaluateDirectors approved a 180,000 bpdprojected $3.2 billion expansion of our Garyville refinery by 180 mbpd to 425 mbpd, which will increase our total refining capacity to 1.154 mmbpd. We recently received air permit approval from the 245,000 bpd Garyville, Louisiana refinery. The initial phaseDepartment of the potential expansion includes FEED work which beganEnvironmental Quality for this project and construction is expected to begin in December 2005 and could lead to the start of

50


construction in 2007. The project, currently estimated to cost approximately $2.2 billion, could be completed as early asmid-2007, with startup planned for the fourth quarter of 2009. The final investment decision is subjectWhen completed, this expansion will enable the refinery to completionprovide an additional 7.5 million gallons of clean transportation fuels to the market each day.

53



        We have also commenced front-end engineering and design for a potential heavy oil upgrading project at our Detroit refinery which would allow us to process increased volumes of Canadian oil sand production and are undertaking a feasibility study for a similar upgrading project at our Catlettsburg refinery.

        In 2006, we signed a definitive agreement forming a joint venture that will construct and operate one or more ethanol production plants. Our partner in the joint venture will provide the day-to-day management of the FEED workplants, as well as grain procurement, and distillers dried grain marketing and ethanol management services. This venture will enable us to maintain the receiptreliability of applicable permits.

a portion of our future ethanol supplies. Together with our partner, we selected the venture's initial plan site, Greenville, Ohio, and construction has commenced on a 110 million gallon per year ethanol facility. The facility is expected to be operational as soon as the first quarter of 2008.

        The above discussion includes forward-looking statements with respect to projectionsconcerning the planned expansion of crude oil throughput, the Garyville Louisiana refinery, expansion project,potential heavy oil refining upgrading projects and other related businesses.a joint venture that would construct and operate ethanol plants. Some factors that could affect crude oil throughput include planned and unplanned refinery maintenance projects, the level of refining margins, and other operating considerations. The Garyville refinery expansion project may be affected byand the results of the FEED work,ethanol plant construction, management and development include necessary regulatorygovernment and third party approvals, crude oil supply and transportation logistics, the receipt of applicable permits, continued favorable investment climate, as well as availability of materials and labor, unforeseen hazards such as weather conditions and other risks customarily associated with construction projects once construction begins.projects. The foregoingGaryville project may be further affected by crude oil supply. These factors (among others) could cause actual results to differ materially from those set forth in the forward-looking statements.

Integrated Gas
     Construction of the EG LNG plant is ahead of schedule with shipment of first cargoes of LNG expected in the third quarter of 2007. This project is expected to be one of the lowest cost LNG operations in the Atlantic basin with an all-in LNG operating, capital and feedstock cost of approximately $1 per million British thermal units (“mmbtu”) at the loading flange of the LNG plant. Efforts are underway to acquire additional natural gas supply and expand the utilization of this LNG facility above and beyond the contract to supply 3.4 million metric tons per year to BG Gas Marketing Ltd. for 17 years. We also are seeking additional natural gas supplies in the area to expand the capacity and life of this plant and that could lead to the development of a second LNG train.
     Under the five-year BP supply agreement, BP will supply us with 58 billion cubic feet (bcf) of natural gas per year, as LNG. We will take delivery of the LNG at the Elba Island terminal where we hold rights to deliver and sell up to 58 bcf of natural gas per year, with pricing linked to the Henry Hub index. This supply agreement enables us to fully utilize our capacity rights at Elba Island during the period of this agreement, while affording us the flexibility to access this capacity to commercialize other stranded natural gas resources beyond the term of the BP contract. The agreement commenced in 2005.
     In 2006, we plan to continue exploring and investing in gas technology research, including GTL technology, which was successfully applied in the Catoosa GTL demonstration plant in 2004. In addition to GTL, we are continuing to explore gas technologies, including methanol to power, gas to fuels and compressed natural gas technologies.
     The above discussion contains forward-looking statements with respect to a LNG project and possible expansion thereof. Factors that could affect the LNG project and related facilitiesheavy oil refining upgrading projects include unforeseen problems arising from construction,difficulty in negotiation of definitive agreements, results of front-end engineering and design work, approval of our Board of Directors, inability or delay in obtaining necessary government and third-party approvals, unanticipated changescontinued favorable investment climate, and other geological, operating and economic considerations.

Integrated Gas

        Construction of the LNG production facility in market demandEquatorial Guinea continues ahead of its original schedule with the first shipments of LNG projected for the second quarter of 2007. Construction is nearly complete and commissioning has commenced. We own a 60 percent interest in Equatorial Guinea LNG Holdings Limited. We are currently seeking additional natural gas supplies to allow full utilization of this LNG facility, which is designed to have a higher capacity and a longer life than the current contract to supply 3.4 million metric tons per year for 17 years.

        Once the Equatorial Guinea LNG production facility commences its principal operations and begins to generate revenue, we must assess whether or supply, environmental issues, availability or constructionnot EGHoldings continues to be a variable interest entity ("VIE"). We consolidate EGHoldings because it is a VIE and we are its primary beneficiary. Despite the fact that we hold majority ownership, we would not consolidate EGHoldings if it ceased to be a VIE because the minority shareholders have substantive participating rights. If EGHoldings ceased to be a VIE, we would account for our interest using the equity method of sufficientaccounting.

        In 2006, with our project partners, we awarded a FEED contract for initial work related to a potential second LNG vessels,production facility on Bioko Island, Equatorial Guinea. The FEED work is expected to be completed during 2007. The scope of the FEED work for the potential 4.4 million metric tones per annum LNG facility includes feed gas metering, liquefaction, refrigeration, ethylene storage, boil off gas compression, product transfer to storage and LNG product metering. A final investment decision is expected in early 2008.

        Atlantic Methanol Production Company LLC underwent a scheduled maintenance shutdown in 2006, during which bottlenecks in several parts of the plant were also removed. Deliveries resumed in October 2006 and AMPCO expects to reach its full expansion capacity during 2007.

        The above discussion contains forward looking statements with respect to the timing and levels of production associated with the LNG production facility and the possible expansion thereof. Factors that could affect the LNG production facility include unforeseen problems arising from commissioning of the facilities, unforeseen hazards such as weather conditions.conditions and other operating considerations such as shipping the LNG. In addition to these factors, other factors that could potentially affect the possible expansion of the current LNG projectproduction facility and the development of additional LNG capacity through additional projects include partner approvals, access to sufficient natural gas volumes through exploration or commercial negotiations with other resource owners and access to sufficient regasification capacity. The foregoing factors (among others) could cause actual results to differ materially from those set forth in the forward-looking statements.

54




CorporateAccounting Standards Not Yet Adopted

     Higher foreign income taxes

        In February 2007, the FASB issued SFAS No. 159, "The Fair Value Option for Financial Assets and Financial Liabilities." This statement permits entities to choose to measure many financial instruments and certain other items at fair value that are expectednot currently required to result from our Libyan operations, wherebe measured at fair value. It requires that unrealized gains and losses on items for which the effective tax rate isfair value option has been elected be recorded in excessnet income. The statement also establishes presentation and disclosure requirements designed to facilitate comparisons between entities that choose different measurement attributes for similar types of 90 percent,assets and an increase in the U.K. supplemental corporation tax rate from 10 percent to 20 percentliabilities. For us, SFAS No. 159 will be effective January 1, 2006. Also increasing our overall effective tax rate are2008, and retrospective application is not permitted. Should we elect to apply the incremental taxes associated withfair value option to any eligible items that exist at January 1, 2008, the expected repatriationeffect of foreign earningsthe first remeasurement to fair value would be reported as a cumulative effect adjustment to the U.S.

     Since 2003,opening balance of retained earnings. We are currently evaluating the variable componentprovisions of this statement.

        In September 2006, the FASB issued SFAS No. 157, "Fair Value Measurements." This statement defines fair value, establishes a framework for measuring fair value in generally accepted accounting principles and expands disclosures about fair value measurements. SFAS No. 157 does not require any new fair value measurements but may require some entities to change their measurement practices. For us, SFAS No. 157 will be effective January 1, 2008, with early application permitted. We are currently evaluating the provisions of this statement.

        In September 2006, the FASB issued FASB Staff Position ("FSP") No. AUG AIR-1, "Accounting for Planned Major Maintenance Activities." This FSP prohibits the use of the accrue-in-advance method of accounting for planned major maintenance activities in annual and interim financial reporting periods. We expense such costs in the same annual period as incurred; however, estimated annual major maintenance costs are recognized as expense throughout the year on a pro rata basis. As such, adoption of FSP No. AUG AIR-1 will have no impact on our stock-based compensation awards has hadannual consolidated financial statements. We are required to adopt the FSP effective January 1, 2007. We do not believe the provisions of FSP No. AUG AIR-1 will have a significant impact on our income from operations. We recognize stock-based compensation expense based on the difference between the market price and the grant price of these variable awards each reporting period until settlement. During 2005, we experienced a 66 percent increase in the market price of our common stock. As a result, we recognized $69 million in stock-based compensation expense compared to $30 million for 2004. Due to exercises of these awards during 2005, the number of outstanding variable awards decreased approximately 74 percent. We expect that this change will reduce the impact these variable awards will have on stock-based compensation expense in 2006.

interim consolidated financial statements.

51


Accounting Standards Not Yet Adopted
        In December 2004,July 2006, the FASB issued FASB Interpretation No. 48, "Accounting for Uncertainty in Income Taxes – An Interpretation of FASB Statement No. 109." FIN No. 48 clarifies the accounting for uncertainty in income taxes recognized in an enterprise's financial statements in accordance with SFAS No. 123(R) as109, "Accounting for Income Taxes." FIN No. 48 prescribes a revision of SFAS No. 123, “Accounting for Stock-Based Compensation.” This statement requires entities to measure the cost of employee services received in exchange for an award of equity instruments based on the fair value of the award on the grant date. That cost will be recognized over the period during which an employee is required to provide service in exchangerecognition threshold and measurement attribute for the award, usuallyfinancial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. The new standard also provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, transition and disclosure. For us, the vesting period. In addition, awards classified as liabilities will be remeasured each reporting period. In 2003, we adopted the fair value method for grants made, modified or settled on or afterprovisions of FIN No. 48 are effective January 1, 2003. Accordingly, we2007. We do not expect thebelieve adoption of SFAS No. 123(R) tothis statement will have a materialsignificant effect on our consolidated results of operations, financial position or cash flows. The statement provided for an effective date of July 1, 2005, for us. However, in April 2005, the Securities and Exchange Commission adopted a rule that, for us, defers the effective date until January 1, 2006. We adopted the provisions of this statement January 1, 2006.

        In November 2004,March 2006, the FASB issued SFAS No. 151, “Inventory Costs156, "Accounting for Servicing of Financial Assets – an amendmentAn Amendment of ARBFASB Statement No. 43, Chapter 4.”140." This statement requires that items such as idle facility expense, excessive spoilage, double freight,amends SFAS No. 140, "Accounting for Transfers and re-handling costs beServicing of Financial Assets and Extinguishments of Liabilities," with respect to the accounting for separately recognized as a current-period charge.servicing assets and servicing liabilities. We are required to implement this statement in the first quarter of 2006.adopt SFAS No. 156 effective January 1, 2007. We do not expect the adoption of SFAS No. 151this statement to have a materialsignificant effect on our consolidated results of operations, financial position or cash flows.

     In May 2005, the FASB issued SFAS No. 154, “Accounting Changes and Error Corrections.” SFAS No. 154 requires companies to recognize (1) voluntary changes in accounting principle and (2) changes required by a new accounting pronouncement, when the pronouncement does not include specific transition provisions, retrospectively to prior periods’ financial statements, unless it is impracticable to determine either the period-specific effects or the cumulative effect of the change. SFAS No. 154 is effective for accounting changes and corrections of errors made in fiscal years beginning after December 15, 2005.
     In September 2005, the FASB ratified the consensus reached by the Emerging Issues Task Force regarding Issue No. 04-13, “Accounting for Purchases and Sales of Inventory with the Same Counterparty.” The issue defines when a purchase and a sale of inventory with the same party that operates in the same line of business is recorded at fair value or considered a single nonmonetary transaction subject to the fair value exception of APB Opinion No. 29. The purchase and sale transactions may be pursuant to a single contractual arrangement or separate contractual arrangements and the inventory purchased or sold may be in the form of raw materials,work-in-process, or finished goods. In general, two or more transactions with the same party are treated as one if they are entered into in contemplation of each other. The rules apply to new arrangements entered into in reporting periods beginning after March 15, 2006. We are currently studying the provisions of this consensus to determine the impact on our consolidated financial statements.

        In February 2006, the FASB issued SFAS No. 155, “Accounting"Accounting for Certain Hybrid Financial Instruments – an amendmentAn Amendment of FASB Statements No. 133 and 140." SFAS No. 155 simplifies the accounting for certain hybrid financial instruments, eliminates the FASB’s interim FASB guidance which provides that beneficial interests in securitized financial assets are not subject to the provisions of SFAS No. 133, “Accounting"Accounting for Derivative Instruments and Hedging Activities," and eliminates the restriction on the passive derivative instruments that a qualifying special-purpose entity may hold. For us, SFAS No. 155 is effective for all financial instruments acquired or issued on or after the beginning of an entity’s first fiscal year that begins after September 15, 2006.January 1, 2007. We are currently studying the provisionsdo not expect adoption of this Statementstatement to determine the impacthave a significant effect on our consolidated results of operations, financial statements.

position or cash flows.

5255



Item 7A. Quantitative and Qualitative Disclosures about Market Risk

Management Opinion Concerning Derivative Instruments

        Management has authorized the use of futures, forwards, swaps and combinations of options to manage exposure to market fluctuations in commodity prices, interest rates and foreign currency exchange rates.

        We use commodity-based derivatives to manage price risk related to the purchase, production or sale of crude oil, natural gas and refined products. To a lesser extent, we are exposed to the risk of price fluctuations on natural gas liquids and petroleum feedstocks used as raw materials and on purchases of ethanol.

        Our strategy generally has generally been to obtain competitive prices for our products and allow operating results to reflect market price movements dictated by supply and demand. We use a variety of derivative instruments, including option combinations, as part of the overall risk management program to manage commodity price risk in our different businesses. As market conditions change, we evaluate our risk management program and could enter into strategies that assume greater market risk whereby cash settlement of commodity-based derivatives will be based on market prices.

risk.

        Our E&P segment primarily uses commodity derivative instruments selectively to protect against price decreases on portions of our future production when deemed advantageous to do so. We also use derivatives to protect the value of natural gas purchased and injected into storage in support of production operations. We use financialcommodity derivative instruments to manage foreign currency exchange rate exposure on foreign currency denominated capital expenditures, operating expenses and tax payments.

     Our RM&T segment uses commodity derivative instruments:
• to mitigate the price risk:
• between the time foreign and domestic crude oil and other feedstock purchases for refinery supply are priced and when they are actually refined into salable petroleum products,
• associated with anticipated natural gas purchases for refinery use,
• associated with freight on crude oil, feedstocks and refined product deliveries, and
• on fixed price contracts for ethanol purchases;
• to protect the value of excess refined product, crude oil and LPG inventories;
• to protect margins associated with future fixed price sales of refined products to non-retail customers;
• to protect against decreases in future crack spreads; and
• to take advantage of trading opportunities identified in the commodity markets.
     Our IG segment is exposed to market risk associated with the purchase and subsequent resale of natural gas. We use commodity derivative instruments to mitigate the price riskgas on purchased volumes and anticipated sales volumes.

        Our RM&T segment uses commodity derivative instruments:

    to mitigate the price risk:

    between the time foreign and domestic crude oil and other feedstock purchases for refinery supply are priced and when they are actually refined into salable petroleum products,

    on fixed price contracts for ethanol purchases,

    associated with anticipated natural gas purchases for refinery use, and

    associated with freight on crude oil, feedstocks and refined product deliveries;

    to protect the value of excess refined product, crude oil and liquefied petroleum gas inventories;

    to protect margins associated with future fixed price sales of refined products to non-retail customers;

    to protect against decreases in future crack spreads; and

    to take advantage of trading opportunities identified in the commodity markets.

        We use financial derivative instruments to manage foreign currency exchange rate exposure on certain foreign currency denominated capital expenditures.

expenditures, operating expenses and tax payments.

        We use financial derivative instruments to manage certain interest rate risk exposures. As we enter into these derivatives, assessments are made as to the qualification of each transaction for hedge accounting.

        We believe that our use of derivative instruments along with risk assessment procedures and internal controls does not expose us to material risk. However, the use of derivative instruments could materially affect our results of operations in particular quarterly or annual periods. We believe that the use of these instruments will not have a material adverse effect on our consolidated financial position or liquidity.

5356



Commodity Price Risk


Commodity Price Risk
        Sensitivity analyses of the incremental effects on income from operations (“IFO”("IFO") of hypothetical 10 percent and 25 percent changes in commodity prices for open derivative commodity instruments as of December 31, 20052006 and December 31, 2004,2005, are provided in the following table:

 
  
  
  
  
 
(In millions)

  
  
  
  
 

 
Commodity Derivative Instruments(b)(c):

 10%
 25%
 10%
 25%
 

 
Crude oil(d) $  – $  – $11(e)$25(e)
Natural gas(d)  47(e) 119(e) 78(e) 195(e)
Refined products(d)  11(f) 28(f) 6(e) 15(e)

 
(a)
                 
(In millions)        
 
  Incremental Decrease in IFO
  Assuming a Hypothetical Price
  Change of(a)
   
  2005 2004
     
Derivative Commodity Instruments(b)(c)  10%  25%  10%  25%
 
Crude oil(d)
 $11(e) $25(e) $1(e) $–  
Natural gas(d)
  78(e)  195(e)  36(e)  91(e)
Refined products(d)
  6(e)  15(e)  3(f)  7(f)
 
(a)We remain at risk for future changes in the market value of derivative instruments; however, such risk should be mitigated by price changes in the underlying hedged item. Effects of these offsets are not reported in the sensitivity analyses. Amounts assume hypothetical 10 percent and 25 percent changes in closing commodity prices, excluding basis swaps, for each open contract position at December 31, 2005 and 2004. The hypothetical price changes of 10 percent and 25 percent would result in incremental decreases in income from operations of $90 million and $225 million for 2005 and $48 million and $119 million for 2004 related to long-term natural gas contracts in the United Kingdom that are accounted for as derivative instruments and these amounts are included above in the impact for natural gas. We evaluate our portfolio of derivative commodity instruments on an ongoing basis and add or revise strategies in anticipation of changes in market conditions and in risk profiles. We are also exposed to credit risk in the event of nonperformance by counterparties. The creditworthiness of counterparties is reviewed continuously and master netting agreements are used when practical. Changes to the portfolio after December 31, 2005, would cause future IFO effects to differ from those presented in the table.
(b)Net open contracts for the combined E&P and IG segments varied throughout 2005, from a low of 1,243 contracts at March 10 to a high of 2,192 contracts at January 20, and averaged 1,654 for the year.
We remain at risk for possible changes in the market value of derivative instruments; however, such risk should be mitigated by price changes in the underlying physical commodity. Effects of these offsets are not reflected in the sensitivity analyses. Amounts reflect hypothetical 10 percent and 25 percent changes in closing commodity prices, excluding basis swaps, for each open contract position at December 31, 2006 and 2005. Included in the natural gas impacts shown above are effects related to the long-term U.K. natural gas contracts, which were $54 million in 2006 and $90 million in 2005, for hypothetical price changes of 10 percent and were $138 million in 2006 and $225 million in 2005 for hypothetical price changes of 25 percent. We evaluate our portfolio of derivative commodity instruments on an ongoing basis and add or revise strategies in anticipation of changes in market conditions and in risk profiles. We are also exposed to credit risk in the event of nonperformance by counterparties. The creditworthiness of counterparties is reviewed continuously and master netting agreements are used when practical. Changes to the portfolio after December 31, 2006, would cause future IFO effects to differ from those presented in this table.
(b)
The number of net open contracts for the RM&T segment varied throughout 2005, from a low of 3,621 contracts at December 19 to a high of 28,079 contracts at March 21, and averaged 18,401 for the year. The derivative commodity instruments used and hedging positions taken will vary and, because of these variations in the composition of the portfolio over time, the number of open contracts by itself cannot be used to predict future income effects.
(c)The calculation of sensitivity amounts for basis swaps assumes that the physical and paper indices are perfectly correlated. Gains and losses on options are based on changes in intrinsic value only.
(d)The direction of the price change used in calculating the sensitivity amount for each commodity is based on the largest incremental decrease in IFO when applied to the derivative commodity instruments used to hedge that commodity.
(e)Price increase.
(f)Price decrease.
E&P Segment
     Derivative losses included in the E&P segment were $5varied throughout 2006, from a low of 316 contracts on June 27, 2006 to a high of 1,634 contracts on January 2, 2006, and averaged 1,054 for the year. The number of net open contracts for the RM&T segment varied throughout 2006, from a low of 166 contracts on December 7, 2006 to a high of 25,123 contracts on August 23, 2006, and averaged 13,154 for the year. The derivative commodity instruments used and positions taken will vary and, because of these variations in the composition of the portfolio over time, the number of open contracts by itself cannot be used to predict future income effects.
(c)
The calculation of sensitivity amounts for basis swaps assumes that the physical and paper indices are perfectly correlated. Gains and losses on options are based on changes in intrinsic value only.
(d)
The direction of the price change used in calculating the sensitivity amount for each commodity reflects that which would result in the largest incremental decrease in IFO when applied to the commodity derivative instruments used to hedge that commodity.
(e)
Price increase.
(f)
Price decrease.

E&P Segment

        Derivative gains of $25 million in 2006 and $7 million in 2005 compared to $169and losses of $152 million in 2004 and $110 millionare included in 2003.E&P segment results. Additionally, losses from discontinued cash flow hedges of $3 million are included in 2004 segment results, compared to losses of $8 million in 2003.results. The discontinued cash flow hedge amounts were reclassified from accumulated other comprehensive income or loss as it was no longer probable that the original forecasted transactions would occur.

     Excluded from The results of activities primarily associated with the marketing of our equity natural gas production, which had been presented as part of the Integrated Gas segment prior to 2006, are included in the E&P segment for all periods presented.

        Excluded from E&P segment results were gains of $454 million in 2006 and losses of $386 million in 2005 and $99 million in 2004 and $66 million in 2003 onrelated to long-term natural gas contracts in the U.K.United Kingdom that are accounted for as derivative instruments. For additional information on these U.K. natural gas contracts, see “Fair"Fair Value Estimates”Estimates" on page 34.

     During37.

        At December 31, 2006 and 2005, we havehad no open derivative contracts related to our oil and natural gas production and therefore remained substantially exposed to market prices of commodities. In 2004, we reduced our exposure to market prices of commodities on 26 percent of crude oil production and 7 percent of natural gas production. In 2003, we reduced our exposure to market prices of commodities on 25 percent of crude oil production and 22 percent of natural gas production.

     At December 31, 2005, we had no open derivative contracts related to our oil and gas production and therefore remain exposed to market prices of commodities. We continue to evaluate the commodity price risks related to our production and may enter into commodity derivative instruments when it is deemed advantageous. As a particular but not exclusive example, we may elect to use commodity derivative instruments to achieve minimum price levels on some portion of our production to support capital or acquisition funding requirements.

5457



RM&T Segment

        We do not attempt to qualify commodity derivative instruments used in our RM&T operations for hedge accounting. As a result, we recognize in net income all changes in the fair value of derivatives used in our RM&T operations. DerivativePretax derivative gains orand losses included in RM&T segment income for each of the last three years are summarized in the following table:

              
Strategy(In millions) 2005 2004 2003
 
Mitigate price risk $(57) $(106) $(112)
Protect carrying values of excess inventories  (118)  (98)  (57)
Protect margin on fixed price sales  18   8   5 
Protect crack spread values  (81)  (76)  6 
          
 Subtotal – non-trading activities  (238)  (272)  (158)
Trading activities  (87)  8   (4)
          
 Total net derivative losses $(325) $(264) $(162)
 

Strategy (In millions)

 2006

 2005

 2004

 

 
Mitigate price risk $204 $(57)$(106)
Protect carrying values of excess inventories  200  (118) (98)
Protect margins associated with fixed price sales  (4) 18  8 
Protect crack spread values  –    (81) (76)
  
 
 
 
 Subtotal, non-trading activities  400  (238) (272)
Trading activities  1  (87) 8 
  
 
 
 
 Total net derivative gains (losses) $401 $(325)$(264)

 

        Derivatives used in non-trading activities have an underlying physical commodity transaction. DerivativeSince the majority of RM&T segment derivative contracts are for the sale of commodities, derivative losses generally occur when market prices increase and generallytypically are offset by gains on the underlying physical commodity transactions. Conversely, derivative gains generally occur when market prices decrease and generally are typically offset by losses on the underlying physical commodity transactions.

     In 2005,transactions. The income effect related to derivatives and the income effect related to the underlying physical transactions may not necessarily be recognized in net income in the same period because we realized an $87 million loss ondo not attempt to qualify these commodity derivative instruments associated with trading activitiesfor hedge accounting. The year-to-year change in the net impact of derivatives primarily as a result of unanticipatedreflects changes in crude oil and refined product prices.
IG Segment
     We have used derivative instruments to convert the fixed price of a long-term gas sales contract to market prices. The underlying physical contract is for a specified annual quantity of gas and matures in 2008. Similarly, we will use derivative instruments to convert shorter term (typically less than a year) fixed price contracts to market prices in our ongoing purchase for resale activity; and to hedge purchased gas injected into storage for subsequent resale. Derivative gains included in IG segment income were $12 million in 2005, $17 million in 2004 and $19 million in 2003. Trading activity in the IG segment resulted in losses of $1 million in 2005, $2 million in 2004 and $7 million in 2003 which have been included in the aforementioned amounts.
conditions.

Other Commodity RiskRelated Risks

        We are impacted by basis risk, caused by factors that affect the relationship between commodity futures prices reflected in derivative commodity instruments and the cash market price of the underlying commodity. Natural gas transaction prices are frequently based on industry reference prices that may vary from prices experienced in local markets. For example, New York Mercantile Exchange (“NYMEX”("NYMEX") contracts for natural gas are priced at Louisiana’sLouisiana's Henry Hub, while the underlying quantities of natural gas may be produced and sold in the western United States at prices that do not move in strict correlation with NYMEX prices. If commodity price changes in one region are not reflected in other regions, derivative commodity instruments may no longer provide the expected hedge, resulting in increased exposure to basis risk. These regional price differences could yield favorable or unfavorable results. Over-the counter (“OTC”)Over-the-counter transactions are being used to manage exposure to a portion of basis risk.

        We are impacted by liquidity risk, caused by timing delays in liquidating contract positions due to a potential inability to identify a counterparty willing to accept an offsetting position. Due to the large number of active participants, liquidity risk exposure is relatively low for exchange-traded transactions.

5558


Interest Rate Risk

        We are impacted by interest rate fluctuations which affect the fair value of certain financial instruments. A sensitivity analysis of the projected incremental effect of a hypothetical 10 percent decrease in interest rates is provided in the following table:

                  
(In millions)  
   
  December 31, 2005 December 31, 2004
     
    Incremental   Incremental
  Fair Increase in Fair Increase in
  Value(b) Fair Value(c) Value(b) Fair Value(c)
 
Financial assets (liabilities)(a):
                
 Investments and long-term receivables $268  $–   $266  $–  
 
Interest rate swap agreements(e)
 $(30) $14  $(10) $14 
 
Long-term debt(d)(e)
 $(4,354) $(152) $(4,480) $(164)
 
(a)Fair values of cash and cash equivalents, receivables, notes payable, commercial paper, accounts payable and accrued interest approximate carrying value and are relatively insensitive to changes in interest rates due to the short-term maturity of the instruments. Accordingly, these instruments are excluded from the table.
(b)See Note 17 and 18 to the consolidated financial statements for carrying value of instruments.
(c)For long-term debt, this assumes a 10 percent decrease in the weighted average yield to maturity of our long-term debt at December 31, 2005 and 2004. For interest rate swap agreements, this assumes a 10 percent decrease in the effective swap rate at December 31, 2005 and 2004.
(d)Includes amounts due within one year and the effects of interest rate swaps.
(e)Fair value was based on market prices where available, or current borrowing rates for financings with similar terms and maturities.

(In millions)

  
  
  
  
 

 
 
 December 31, 2006

 December 31, 2005

 
 
 Fair
Value(b)

 Incremental
Increase in
Fair
Value(c)

 Fair
Value(b)

 Incremental
Increase in
Fair
Value(c)

 

 
Financial assets (liabilities)(a):             
 Investments and long-term receivables $461 $–   $268 $–   
 Interest rate swap agreements(d) $(22)$9 $(30)$14 
 Long-term debt(d)(e) $(3,729)$(132)$(4,354)$(152)

 
(a)
Fair values of cash and cash equivalents, receivables, notes payable, commercial paper, accounts payable and accrued interest approximate carrying value and are relatively insensitive to changes in interest rates due to the short-term maturity of the instruments. Accordingly, these instruments are excluded from the table.
(b)
See Notes 18 and 19 to the consolidated financial statements for carrying value of these instruments.
(c)
For long-term debt, this assumes a 10 percent decrease in the weighted average yield to maturity of our long-term debt at December 31, 2006 and 2005. For interest rate swap agreements, this assumes a 10 percent decrease in the effective swap rate at December 31, 2006 and 2005.
(d)
Fair value was based on market prices where available, or current borrowing rates for financings with similar terms and maturities.
(e)
Includes amounts due within one year.

        At December 31, 20052006 and 2004,2005, our portfolio of long-term debt was substantially comprised of fixed rate instruments. Therefore, the fair value of the portfolio is relatively sensitive to the effects of interest rate fluctuations. This sensitivity is illustrated by the $152$132 million increase in the fair value of long-term debt at December 31, 2006, assuming a hypothetical 10 percent decrease in interest rates. However, our sensitivity to interest rate declines and corresponding increases in the fair value of our debt portfolio would unfavorably affect our results of operations and cash flows only ifwhen we would elect to repurchase or otherwise retire all or a portion of its fixed-rate debt portfolio at prices above carrying value.

        We manage our exposure to interest rate movements by utilizing financial derivative instruments. The primary objective of this program is to reduce our overall cost of borrowing by managing the fixed and floating interest rate mix of the debt portfolio. We have entered into several interest rate swap agreements, designated as fair value hedges, which effectively resulted in an exchange of existing obligations to pay fixed interest rates for obligations to pay floating rates. The following table summarizes by individual debt instrument, theour interest rate swap activityswaps as of December 31, 2005:

                 
  Fixed Rate to be Notional Swap  
Floating Rate to be Paid Received Amount Maturity Fair Value
 
Six Month LIBOR +4.226%  6.650% $300  million   2006  $(1) million 
Six Month LIBOR +1.935%  5.375% $450  million   2007  $(8) million 
Six Month LIBOR +3.285%  6.850% $400  million   2008  $(11) million 
Six Month LIBOR +2.142%  6.125% $200  million   2012  $(10) million 
 
2006:

(Dollars in millions)

  
  
  
  
 

 
Floating Rate to be Paid

 Fixed Rate
to be
Received

 Notional
Amount

 Swap
Maturity

 Fair Value

 

 
Six Month LIBOR +1.935% 5.375%$450 2007 $(4)
Six Month LIBOR +3.285% 6.850%$400 2008 $(8)
Six Month LIBOR +2.142% 6.125%$200 2012 $(10)

 

5659


Foreign Currency Exchange Rate Risk

        We manage our exposure to foreign currency exchange rates by utilizing forward and option contracts, generally with terms of 365 days or less.contracts. The primary objective of this program is to reduce our exposure to movements in the foreign currency markets by locking in foreign currency rates. At December 31, 2005,2006, the following currency derivatives were outstanding. All contracts currently qualify for hedge accounting unless noted.

NotionalCollar StrikeFair
Financial InstrumentsPeriodAmountRange(a)Value(b)
Foreign Currency Rate Option
Collars
EuroJanuary 2006 – June 2006$81 million1.17 – 1.22(c)$– 
Norwegian kronerJanuary 2006 – June 2006$154  million6.42 – 6.95(d)$– 
(a)Rates shown are weighted average floor and ceiling prices for the period. If exchange rates are within the specified collar range at expiration, the collar expires worthless. If exchange rates are outside of the various collar ranges at expiration, we will settle the difference with the counterparty.
(b)Fair value was based on market prices.
(c)U.S. dollar to foreign currency.
(d)Foreign currency to U.S. dollar.
accounting.

(Dollars in millions)

  
  
  
  

 
 Period

 Notional
Amount

 Forward
Rate
(a)

 Fair Value(b)


Foreign Currency Rate Forwards:          
 Euro July 2007 – November 2008 $51 1.255(c)$3
 Kroner (Norway) January 2007 – October 2009 $127 6.213(d)$  –

(a)
Rates shown are weighted average all-in forward rates for the period.
(b)
Fair value was based on market rates.
(c)
U.S. dollar to foreign currency.
(d)
Foreign currency to U.S. dollar.

        The aggregate effect on foreign exchange and optioncurrency forward contracts of a hypothetical 10 percent change to year-end exchange rates at December 31, 2006, would be approximately $15$14 million.

Credit Risk

        We are exposed to significant credit risk from United States Steel arising from the Separation. That exposure is discussed in “Management’sManagement's Discussion and Analysis of Financial Condition and Results of Operations – Obligations Associated with the Separation of United States Steel”.

Steel.

Safe Harbor

        These quantitative and qualitative disclosures about market risk include forward-looking statements with respect to management’smanagement's opinion about risks associated with the use of derivative instruments. These statements are based on certain assumptions with respect to market prices and industry supply of and demand for crude oil, natural gas, refined products and other feedstocks. If these assumptions prove to be inaccurate, future outcomes with respect to our hedging programs may differ materially from those discussed in the forward-looking statements.

5760



Item 8. Financial Statements and Supplementary Data

    MARATHON OIL CORPORATION


Index to 2006 Consolidated Financial Statements and Supplementary Data


Index to 2005 Consolidated Financial Statements and Supplementary Data
Page
F-2
F-2
F-3
 F-4
 F-5
 F-6
 F-7
 F-8
F-42
F-42
F-43
F-50
F-52

F-1

F-1



                   Management’sManagement's Responsibilities for Financial Statements

      To the Stockholders of Marathon Oil Corporation:

              The accompanying consolidated financial statements of Marathon Oil Corporation and its consolidated subsidiaries ("Marathon") are the responsibility of management and have been prepared in conformity with accounting principles generally accepted in the United States of America. They necessarily include some amounts that are based on best judgments and estimates. The financial information displayed in other sections of this Annual Report on Form 10-K is consistent with these consolidated financial statements.

              Marathon seeks to assure the objectivity and integrity of its financial records by careful selection of its managers, by organizational arrangements that provide an appropriate division of responsibility and by communications programs aimed at assuring that its policies and methods are understood throughout the organization.

              The Board of Directors pursues its oversight role in the area of financial reporting and internal control over financial reporting through its Audit Committee. This Committee, composed solely of independent directors, regularly meets (jointly and separately) with the independent registered public accounting firm, management and internal auditors to monitor the proper discharge by each of their responsibilities relative to internal accounting controls and the consolidated financial statements.

To the Stockholders of Marathon Oil Corporation:
     The accompanying consolidated financial statements of Marathon Oil Corporation and its consolidated subsidiaries (“Marathon”) are the responsibility of management and have been prepared in conformity with accounting principles generally accepted in the United States of America. They necessarily include some amounts that are based on best judgments and estimates. The financial information displayed in other sections of this Annual Report on Form 10-K is consistent with these consolidated financial statements.
     Marathon seeks to assure the objectivity and integrity of its financial records by careful selection of its managers, by organizational arrangements that provide an appropriate division of responsibility and by communications programs aimed at assuring that its policies and methods are understood throughout the organization.
     The Board of Directors pursues its oversight role in the area of financial reporting and internal control over financial reporting through its Audit Committee. This Committee, composed solely of independent directors, regularly meets (jointly and separately) with the independent registered public accounting firm, management and internal auditors to monitor the proper discharge by each of their responsibilities relative to internal accounting controls and the consolidated financial statements.
  
Clarence P. Cazalot, Jr.Janet F. ClarkAlbert G. Adkins

President and
Senior Vice President
Vice President,

Chief Executive Officer
 
Janet F. Clark
Executive Vice President
and Chief Financial Officer
 
Michael K. Stewart
Vice President, Accounting
and Controller


                   Management’sManagement's Report on Internal Control over Financial Reporting

      To the Stockholders of Marathon Oil Corporation:

              Marathon's management is responsible for establishing and maintaining adequate internal control over financial reporting (as defined in Rule 13a – 15(f) under the Securities Exchange Act of 1934). An evaluation of the design and effectiveness of our internal control over financial reporting, based on the framework inInternal Control – Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission, was conducted under the supervision and the participation of management, including our Chief Executive Officer and Chief Financial Officer. Based on the results of this evaluation, Marathon's management concluded that its internal control over financial reporting was effective as of December 31, 2006.

              Marathon's management assessment of the effectiveness of Marathon's internal control over financial reporting as of December 31, 2006 has been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, as stated in their report which is included herein.

To the Stockholders of Marathon Oil Corporation:
     Marathon’s management is responsible for establishing and maintaining adequate internal control over financial reporting (as defined in Rule 13a – 15(f) under the Securities Exchange Act of 1934). An evaluation of the design and effectiveness of our internal control over financial reporting, based on the framework inInternal Control – Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission, was conducted under the supervision and the participation of management, including our Chief Executive Officer and Chief Financial Officer. Based on the results of this evaluation, Marathon’s management concluded that its internal control over financial reporting was effective as of December 31, 2005. This evaluation did not include the internal control over financial reporting related to Marathon’s Libya operations acquired in a purchase business combination on December 29, 2005. Under the terms of the agreement, the operational re-entry date is January 1, 2006; therefore, Marathon’s consolidated results of operations for 2005 do not include any results from the Libya operations. Total assets recorded for the Libya operations as of December 31, 2005 represent approximately 4 percent of total assets as of that date.
     Marathon’s management assessment of the effectiveness of Marathon’s internal control over financial reporting as of December 31, 2005 has been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, as stated in their report which is included herein.
   
Clarence P. Cazalot, Jr.Janet F. Clark

President and
Senior Vice President

Chief Executive Officer
 
Janet F. Clark
Executive Vice President
and Chief Financial Officer
  

F-2

F-2



                   Report of Independent Registered Public Accounting Firm

To the Stockholders of Marathon Oil Corporation:
     We have completed integrated audits of Marathon Oil Corporation and its subsidiaries’ (Marathon) 2005 and 2004 consolidated financial statements and of its internal control over financial reporting as of December 31, 2005, and an audit of its 2003 consolidated financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Our opinions, based on our audits, are presented below.

      To the Stockholders of Marathon Oil Corporation:

              We have completed integrated audits of Marathon Oil Corporation's consolidated financial statements and of its internal control over financial reporting as of December 31, 2006, in accordance with the standards of the Public Company Accounting Oversight Board (United States). Our opinions, based on our audits, are presented below.

                   Consolidated financial statements

              In our opinion, the consolidated financial statements listed in the accompanying index present fairly, in all material respects, the financial position of Marathon Oil Corporation and its subsidiaries at December 31, 2006 and 2005, and the results of their operations and their cash flows for each of the three years in the period ended December 31, 2006 in conformity with accounting principles generally accepted in the United States of America. These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits of these statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit of financial statements includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

              As discussed in Note 2 to the consolidated financial statements, the Company changed its methods of accounting for purchases and sales of inventory with the same counterparty and defined benefit pension and other postretirement plans in 2006 and its method of accounting for conditional asset retirement obligations in 2005.

                   Internal control over financial reporting

              Also, in our opinion, management's assessment, included in Management's Report on Internal Control over Financial Reporting, appearing herein, that the Company maintained effective internal control over financial reporting as of December 31, 2006 based on criteria established inInternal Control – Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO), is fairly stated, in all material respects, based on those criteria. Furthermore, in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2006, based on criteria established inInternal Control – Integrated Framework issued by the COSO. The Company's management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting. Our responsibility is to express opinions on management's assessment and on the effectiveness of the Company's internal control over financial reporting based on our audit. We conducted our audit of internal control over financial reporting in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. An audit of internal control over financial reporting includes obtaining an understanding of internal control over financial reporting, evaluating management's assessment, testing and evaluating the design and operating effectiveness of internal control, and performing such other procedures as we consider necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinions.

              A company's internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company's internal control over financial reporting includes those policies and procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company's assets that could have a material effect on the financial statements.

              Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

      PricewaterhouseCoopers LLP
      Houston, Texas
      February 28, 2007

F-3


    Consolidated financial statements
         In our opinion, the accompanying consolidated financial statements present fairly, in all material respects, the financial position of Marathon at December 31, 2005 and 2004, and the results of their operations and their cash flows for each of the three years in the period ended December 31, 2005 in conformity with accounting principles generally accepted in the United States of America. These financial statements are the responsibility of Marathon’s management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits of these statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit of financial statements includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.
         As discussed in Note 2 to the financial statements, Marathon changed its method of accounting for conditional asset retirement obligations in 2005 and its method of accounting for asset retirement obligations in 2003.
    Internal control over financial reporting
         Also, in our opinion, management’s assessment, included in the accompanying Management’s Report on Internal Control over Financial Reporting, that Marathon maintained effective internal control over financial reporting as of December 31, 2005 based on criteria established inInternal Control – Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO), is fairly stated, in all material respects, based on those criteria. Furthermore, in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2005, based on criteria established inInternal Control – Integrated Framework issued by the COSO. Marathon’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting. Our responsibility is to express opinions on management’s assessment and on the effectiveness of Marathon’s internal control over financial reporting based on our audit. We conducted our audit of internal control over financial reporting in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. An audit of internal control over financial reporting includes obtaining an understanding of internal control over financial reporting, evaluating management’s assessment, testing and evaluating the design and operating effectiveness of internal control, and performing such other procedures as we consider necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinions.
         A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.
         Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.
         As described in the accompanying Management’s Report on Internal Control over Financial Reporting, management has excluded Marathon’s Libya operations from its assessment of internal control over financial reporting as of December 31, 2005 because it was acquired by Marathon in a purchase business combination in December 2005. We have also excluded the Libya operations from our audit of internal control over financial reporting. The Libya operations’ total assets and total revenues represent 4% and 0%, respectively, of the related consolidated financial statement amounts as of and for the year ended December 31, 2005.
    PricewaterhouseCoopers LLP
    Houston, Texas
    March 3, 2006

    F-3



    Consolidated Statement of Income

    (Dollars in millions except per share data)

     2006
     2005
     2004
     

     
    Revenues and other income:          
     Sales and other operating revenues (including consumer excise taxes) $57,973 $48,948 $39,172 
     Revenues from matching buy/sell transactions  5,457  12,636  9,242 
     Sales to related parties  1,466  1,402  1,051 
     Income from equity method investments  391  265  167 
     Net gains on disposal of assets  77  57  36 
     Gain on ownership change in Marathon Petroleum Company LLC      2 
     Other income  85  37  100 
      
     
     
     
       Total revenues and other income  65,449  63,345  49,770 
      
     
     
     
    Costs and expenses:          
     Cost of revenues (excludes items shown below)  42,415  37,806  30,700 
     Purchases related to matching buy/sell transactions  5,396  12,364�� 9,050 
     Purchases from related parties  210  225  202 
     Consumer excise taxes  4,979  4,715  4,463 
     Depreciation, depletion and amortization  1,518  1,303  1,178 
     Selling, general and administrative expenses  1,228  1,155  1,021 
     Other taxes  371  318  282 
     Exploration expenses  365  217  158 
      
     
     
     
       Total costs and expenses  56,482  58,103  47,054 
      
     
     
     
    Income from operations  8,967  5,242  2,716 
    Net interest and other financing costs (income)  (37) 146  162 
    Loss on early extinguishment of debt  35     
    Minority interests in income (loss) of:          
     Marathon Petroleum Company LLC    384  532 
     Equatorial Guinea LNG Holdings Limited  (10) (8) (7)
      
     
     
     
    Income from continuing operations before income taxes  8,979  4,720  2,029 
    Provision for income taxes  4,022  1,714  735 
      
     
     
     
    Income from continuing operations  4,957  3,006  1,294 

    Discontinued operations

     

     

    277

     

     

    45

     

     

    (33

    )
      
     
     
     
    Income before cumulative effect of change in accounting principle  5,234  3,051  1,261 
    Cumulative effect of change in accounting principle    (19)  
      
     
     
     
    Net income $5,234 $3,032 $1,261 

     

    Per Share Data

     

     

     

     

     

     

     

     

     

     
     Basic:          
      Income from continuing operations $13.85 $8.44 $3.85 
      Net income $14.62 $8.52 $3.75 
     Diluted:          
      Income from continuing operations $13.73 $8.37 $3.83 
      Net income $14.50 $8.44 $3.73 

     

        Consolidated Statements of Income

                   
    (Dollars in millions, except per share data) 2005 2004 2003
     
    Revenues and other income:
                
     Sales and other operating revenues (including consumer excise taxes) $49,273  $39,305  $32,859 
     Revenues from matching buy/sell transactions  12,636   9,242   7,183 
     Sales to related parties  1,402   1,051   921 
     Income from equity method investments  266   170   29 
     Net gains on disposal of assets  57   36   166 
     Gain (loss) on ownership change in Marathon Petroleum Company LLC  –     2   (1)
     Other income – net  39   101   77 
                 
      Total revenues and other income  63,673   49,907   41,234 
                 
    Costs and expenses:
                
     Cost of revenues (excluding items shown below)  37,847   30,740   24,900 
     Purchases related to matching buy/sell transactions  12,364   9,050   7,213 
     Purchases from related parties  225   202   209 
     Consumer excise taxes  4,715   4,463   4,285 
     Depreciation, depletion and amortization  1,358   1,217   1,144 
     Selling, general and administrative expenses  1,158   1,025   920 
     Other taxes  482   338   299 
     Exploration expenses  222   202   180 
                 
      Total costs and expenses  58,371   47,237   39,150 
                 
    Income from operations
      5,302   2,670   2,084 
    Net interest and other financing costs  145   161   186 
    Minority interests in income (loss) of:            
     Marathon Petroleum Company LLC  384   532   302 
     Equatorial Guinea LNG Holdings Limited  (8)  (7)  –   
                 
    Income from continuing operations before income taxes
      4,781   1,984   1,596 
    Provision for income taxes  1,730   727   584 
                 
    Income from continuing operations
      3,051   1,257   1,012 
    Discontinued operations
      –     4   305 
                 
    Income before cumulative effect of changes in accounting principles
      3,051   1,261   1,317 
    Cumulative effect of changes in accounting principles  (19)  –     4 
                 
    Net income
     $3,032  $1,261  $1,321 
     
    Per Share Data
                
     
    Basic:
                
      Income from continuing operations $8.57  $3.74  $3.26 
      Net income $8.52  $3.75  $4.26 
     
    Diluted:
                
      Income from continuing operations $8.49  $3.72  $3.26 
      Net income $8.44  $3.73  $4.26 
     
    The accompanying notes are an integral part of these consolidated financial statements.

    F-4


      F-4



      Consolidated Balance SheetsSheet

      (Dollars in millions, except per share data)

       December 31
       2006
       2005
       

       
      Assets         
      Current assets:         
       Cash and cash equivalents   $2,585 $2,617 
       Receivables, less allowance for doubtful accounts of $3 and $3    4,114  3,476 
       Receivables from United States Steel    32  20 
       Receivables from related parties    63  38 
       Inventories    3,173  3,041 
       Other current assets    129  191 
          
       
       
         Total current assets    10,096  9,383 
      Investments and long-term receivables, less allowance for doubtful accounts of $9 and $10    1,887  1,864 
      Receivables from United States Steel    498  532 
      Property, plant and equipment, net    16,653  15,011 
      Goodwill    1,398  1,307 
      Intangible assets, net    180  200 
      Other noncurrent assets    119  201 
          
       
       
         Total assets   $30,831 $28,498 

       
      Liabilities         
      Current liabilities:         
       Accounts payable   $5,586 $5,353 
       Consideration payable under Libya re-entry agreement      732 
       Payable to United States Steel    13   
       Payables to related parties    264  82 
       Payroll and benefits payable    409  344 
       Accrued taxes    598  782 
       Deferred income taxes    631  450 
       Accrued interest    89  96 
       Long-term debt due within one year    471  315 
          
       
       
         Total current liabilities    8,061  8,154 
      Long-term debt    3,061  3,698 
      Deferred income taxes    1,897  2,030 
      Defined benefit postretirement plan obligations    1,245  1,251 
      Asset retirement obligations    1,044  711 
      Payable to United States Steel    7  6 
      Deferred credits and other liabilities    391  508 
          
       
       
         Total liabilities    15,706  16,358 
      Minority interests in Equatorial Guinea LNG Holdings Limited    518  435 
      Commitments and contingencies         

      Stockholders' Equity

       

       

       

       

       

       

       

       

       
      Common stock issued – 367,851,558 and 366,925,852 shares (par value $1 per share, 550,000,000 shares authorized)    368  367 
      Common stock held in treasury, at cost – 20,080,670 and 179,977 shares  (1,638) (8)
      Additional paid-in capital    5,152  5,111 
      Retained earnings    11,093  6,406 
      Accumulated other comprehensive loss    (368) (151)
      Unearned compensation      (20)
          
       
       
         Total stockholders' equity    14,607  11,705 
          
       
       
         Total liabilities and stockholders' equity   $30,831 $28,498 

       

                           The accompanying notes are an integral part of these consolidated financial statements.

                 
      (Dollars in millions, except per share data)December 31     2005 2004
       
      Assets
              
      Current assets:        
       Cash and cash equivalents $2,617  $3,369 
       Receivables, less allowance for doubtful accounts of $3 and $6  3,476   3,146 
       Receivables from United States Steel  20   15 
       Receivables from related parties  38   74 
       Inventories  3,041   1,995 
       Other current assets  191   267 
               
        Total current assets  9,383   8,866 
      Investments and long-term receivables, less allowance for doubtful
      accounts of $10 and $10
        1,864   1,546 
      Receivables from United States Steel  532   587 
      Property, plant and equipment – net  15,011   11,810 
      Prepaid pensions  –    128 
      Goodwill  1,307   252 
      Intangibles – net  200   118 
      Other noncurrent assets  201   116 
               
        Total assets $28,498  $23,423 
       
      Liabilities
              
      Current liabilities:        
       Accounts payable $5,353  $4,430 
       Consideration payable under Libya re-entry agreement  732   –  
       Payables to related parties  82   44 
       Payroll and benefits payable  344   274 
       Accrued taxes  782   397 
       Deferred income taxes  450   –  
       Accrued interest  96   92 
       Long-term debt due within one year  315   16 
               
        Total current liabilities  8,154   5,253 
      Long-term debt  3,698   4,057 
      Deferred income taxes  2,030   1,553 
      Employee benefit obligations  1,321   989 
      Asset retirement obligations  711   477 
      Payables to United States Steel  6   5 
      Deferred credits and other liabilities  438   288 
               
        Total liabilities  16,358   12,622 
      Minority interest in Marathon Petroleum Company LLC  –    2,559 
      Minority interests in Equatorial Guinea LNG Holdings Limited  435   131 
      Commitments and contingencies        
      Stockholders’ Equity
              
      Common stock issued – 366,925,852 shares at December 31, 2005 and 346,717,785 shares at December 31, 2004 (par value $1 per share, 550,000,000 shares authorized)  367   347 
      Common stock held in treasury, at cost – 179,977 shares at December 31, 2005 and 34,650 shares at December 31, 2004  (8)  (1)
      Additional paid-in capital  5,111   4,028 
      Retained earnings  6,406   3,810 
      Accumulated other comprehensive loss  (151)  (64)
      Unearned compensation  (20)  (9)
               
        Total stockholders’ equity  11,705   8,111 
               
        Total liabilities and stockholders’ equity $28,498  $23,423 
       

      F-5



      Consolidated Statement of Cash Flows

      (Dollars in millions)

       2006
       2005
       2004
       

       
      Increase (decrease) in cash and cash equivalents          
      Operating activities:          
      Net income $5,234 $3,032 $1,261 
      Adjustments to reconcile net income to net cash provided from operating activities:          
       Loss on early extinguishment of debt  35  –    –   
       Cumulative effect of change in accounting principle  –    19  –   
       Income from discontinued operations  (277) (45) 33 
       Deferred income taxes  268  (205) (62)
       Minority interests in income (loss) of subsidiaries  (10) 376  525 
       Depreciation, depletion and amortization  1,518  1,303  1,178 
       Pension and other postretirement benefits, net  (404) 71  82 
       Exploratory dry well costs and unproved property impairments  166  111  68 
       Net gains on disposal of assets  (77) (57) (36)
       Equity method investments, net  (200) (65) (15)
       Changes in the fair value of long-term U.K. natural gas contracts  (454) 386  99 
       Changes in:          
        Current receivables  (535) (1,164) (691)
        Inventories  (133) (150) (40)
        Current accounts payable and accrued expenses  237  1,065  1,197 
       All other, net  50  (22) 137 
        
       
       
       
        Net cash provided from continuing operations  5,418  4,655  3,736 
        Net cash provided from discontinued operations  70  83  30 
        
       
       
       
        Net cash provided from operating activities  5,488  4,738  3,766 
        
       
       
       
      Investing activities:          
      Capital expenditures  (3,433) (2,796) (2,141)
      Acquisitions  (741) (506) –   
      Disposal of discontinued operations  832  –    –   
      Proceeds from sale of minority interests in Equatorial Guinea LNG Holdings Limited  –    163  –   
      Disposal of assets  134  131  76 
      Restricted cash – deposits  (19) (54) (42)
      Restricted cash – withdrawals  43  41  34 
      Investments – loans and advances  (17) (28) (160)
                              – repayments of loans and advances  298  15  15 
      Investing activities of discontinued operations  (45) (94) (106)
      All other, net  (7) 1  –   
        
       
       
       
        Net cash used in investing activities  (2,955) (3,127) (2,324)
        
       
       
       
      Financing activities:          
      Payment of debt assumed in acquisition  –    (1,920) –   
      Debt issuance costs  –    –    (4)
      Other debt repayments  (501) (8) (259)
      Issuance of common stock  50  78  1,043 
      Purchases of common stock  (1,698) –    –   
      Excess tax benefits from stock-based compensation arrangements  35  –    –   
      Dividends paid  (547) (436) (348)
      Contributions from minority shareholders of Equatorial Guinea LNG Holdings Limited  80  213  95 
      Distributions to minority shareholder of Marathon Petroleum Company LLC  –    (272) –   
        
       
       
       
        Net cash provided from (used in) financing activities  (2,581) (2,345) 527 
        
       
       
       
      Effect of exchange rate changes on cash  16  (18) 4 
        
       
       
       
      Net increase (decrease) in cash and cash equivalents  (32) (752) 1,973 
      Cash and cash equivalents at beginning of year  2,617  3,369  1,396 
        
       
       
       
      Cash and cash equivalents at end of year $2,585 $2,617 $3,369 

       

                           The accompanying notes are an integral part of these consolidated financial statements.

      F-6



      Consolidated Statement of Stockholders' Equity

       
       Stockholders' Equity
       Shares in thousands
       
      (Dollars in millions, except per share data)

       2006
       2005
       2004
       2006
       2005
       2004
       

       
      Common stock issued                   
       Balance at beginning of year $367 $347 $312  366,926  346,718  312,166 
       Issuances(a)  1  20  35  926  20,208  34,552 
        
       
       
       
       
       
       
       Balance at end of year $368 $367 $347  367,852  366,926  346,718 

       
      Common stock held in treasury, at cost                   
       Balance at beginning of year $(8)$(1)$(46) (180) (35) (1,744)
       Repurchases  (1,698) (7) (4) (20,745) (10) (129)
       Reissuances for employee stock plans  68  –    49  844  (135) 1,838 
        
       
       
       
       
       
       
       Balance at end of year $(1,638)$(8)$(1) (20,081) (180) (35)

       
       
        
        
        
       Comprehensive Income
       

       


       

       


       

       


       

       


       

      2006

       

      2005

       

      2004

       

       
      Additional paid-in capital                   
       Balance at beginning of year $5,111 $4,028 $3,033          
       Stock issuances(a)  (7) 1,048  983          
       Stock-based compensation expense  48  35  12          
        
       
       
                
       Balance at end of year $5,152 $5,111 $4,028          

                
      Unearned compensation                   
       Balance at beginning of year $(20)$(9)$(9)         
       Change in accounting principle  20  –    –            
       Changes during year  –    (11) –            
        
       
       
                
       Balance at end of year $–   $(20)$(9)         

                
      Retained earnings                   
       Balance at beginning of year $6,406 $3,810 $2,897          
       Net income  5,234  3,032  1,261 $5,234 $3,032 $1,261 
       Dividends paid (per share: $1.53 in 2006, $1.22 in 2005 and $1.03 in 2004)  (547) (436) (348)         
        
       
       
                
       Balance at end of year $11,093 $6,406 $3,810          

                
      Accumulated other comprehensive loss                   
       Minimum pension liability adjustments:                   
        Balance at beginning of year $(141)$(71)$(93)         
        Changes during year, net of tax of $74, $42 and $3  114  (70) 22  114  (70) 22 
        Reclassification to defined benefit postretirement plans  27  –    –            
        
       
       
                
        Balance at end of year $–   $(141)$(71)         
       Defined benefit postretirement plans:                   
        Balance at beginning of year $–   $–   $–            
        Reclassification from minimum pension liability adjustments  (27) –    –            
        Change in accounting principle, net of tax of $289  (348) –    –            
        
       
       
                
        Balance at end of year $(375)$–   $–            
       Deferred gains (losses) on derivative instruments:                   
        Balance at beginning of year $(5)$12 $(15)         
        Reclassification of the cumulative effect adjustment into net income, net of tax of $–, $– and $1  (2) (2) (3) (2) (2) (3)
        Changes in fair value, net of tax of $1, $3 and $20  4  (15) (82) 4  (15) (82)
        Reclassification to net income, net of tax of $–, $– and $30  1  –    112  1  –    112 
        
       
       
                
        Balance at end of year $(2)$(5)$12          
        
       
       
                
       Other:                   
        Balance at beginning of year $(5)$(5)$(4)         
        Changes during year, net of tax of $8, $– and $–  14  –    (1) 9  –    (1)
        
       
       
                
        Balance at end of year $9 $(5)$(5)         
        
       
       
                
         Total at end of year $(368)$(151)$(64)         

       
          Comprehensive income          $5,360 $2,945 $1,309 

       
      Total stockholders' equity $14,607 $11,705 $8,111          

                
      (a) On March 31, 2004, Marathon issued 34,500,000 shares of its common stock at the offering price of $30 per share and recorded net proceeds of $1.004 billion. On June 30, 2005, in connection with the acquisition of Ashland Inc.'s minority interest in Marathon Petroleum Company LLC, Marathon distributed 17,538,815 shares of its common stock valued at $54.45 per share to Ashland's shareholders. 

          The accompanying notes are an integral part of these consolidated financial statements.

      F-7


        F-5Notes to Consolidated Financial Statements


        Consolidated Statements of Cash Flows
                        
        (Dollars in millions) 2005 2004 2003
         
        Increase (decrease) in cash and cash equivalents
                    
        Operating activities
                    
        Net income $3,032  $1,261  $1,321 
        Adjustments to reconcile net income to net cash provided from operating activities:            
         Cumulative effect of changes in accounting principles  19   –    (4)
         Income from discontinued operations  –    (4)  (305)
         Deferred income taxes  (208)  (73)  71 
         Minority interests in income of subsidiaries  376   525   302 
         Depreciation, depletion and amortization  1,358   1,217   1,144 
         Pension and other postretirement benefits – net  71   82   68 
         Exploratory dry well costs and unproved property impairments  113   106   86 
         Net gains on disposal of assets  (57)  (36)  (166)
         Impairment of investments  –    –    129 
         Changes in the fair value of long-term U.K. natural gas contracts  386   99   66 
         Changes in working capital:            
          Current receivables  (1,171)  (709)  (671)
          Inventories  (150)  (41)  33 
          Current accounts payable and accrued expenses  1,067   1,224   496 
         All other – net  (98)  115   112 
                  
          Net cash provided from continuing operations  4,738   3,766   2,682 
          Net cash provided from discontinued operations  –    –    83 
                  
          Net cash provided from operating activities  4,738   3,766   2,765 
                  
        Investing activities
                    
        Capital expenditures  (2,890)  (2,247)  (1,909)
        Acquisitions  (506)  –    (252)
        Disposal of discontinued operations  –    –    612 
        Disposal of assets  131   76   644 
        Proceeds from sale of minority interests in Equatorial Guinea LNG Holdings Limited  163   –    –  
        Restricted cash – deposits  (54)  (42)  (108)
           – withdrawals  41   34   146 
        Investments – loans and advances  (27)  (156)  (91)
        All other – net  15   11   2 
        Investing activities of discontinued operations  –    –    (29)
                  
          Net cash used in investing activities  (3,127)  (2,324)  (985)
                  
        Financing activities
                    
        Payment of debt assumed in acquisitions  (1,920)  –    (31)
        Commercial paper and revolving credit arrangements – net  –    –    (131)
        Debt issuance costs  –    (4)  –  
        Other debt repayments  (8)  (259)  (177)
        Issuance of common stock  85   1,047   17 
        Purchases of common stock  (7)  (4)  (6)
        Dividends paid  (436)  (348)  (298)
        Contributions from minority shareholders of Equatorial Guinea LNG Holdings Limited  213   95   –  
        Distributions to minority shareholder of Marathon Petroleum Company LLC  (272)  –    (262)
                  
          Net cash provided from (used in) financing activities  (2,345)  527   (888)
                  
        Effect of exchange rate changes on cash
                    
        Continuing operations  (18)  4   8 
        Discontinued operations  –    –    8 
                  
        Net increase (decrease) in cash and cash equivalents
          (752)  1,973   908 
        Cash and cash equivalents at beginning of year
          3,369   1,396   488 
                  
        Cash and cash equivalents at end of year
         $2,617  $3,369  $1,396 
         
        The accompanying notes are an integral part of these consolidated financial statements.

        F-6


        Consolidated Statements of Stockholders’ Equity
                                     
          Stockholders’ Equity Shares in thousands
             
        (Dollars in millions, except per share data) 2005 2004 2003 2005 2004 2003
         
        Common stock:
                                
         Balance at beginning of year $347  $312  $312   346,718   312,166   312,166 
         
        Issuance(a)
          20   35   –    20,208   34,552   –  
                           
         Balance at end of year $367  $347  $312   366,926   346,718   312,166 
                           
        Common stock held in treasury, at cost:
                                
         Balance at beginning of year $(1) $(46) $(60)  (35)  (1,744)  (2,293)
         Repurchased  (7)  (4)  (6)  (10)  (129)  (219)
         Reissued for employee stock plans  –    49   20   (135)  1,838   768 
                           
         Balance at end of year $(8) $(1) $(46)  (180)  (35)  (1,744)
         
                                     
                Comprehensive Income
                 
                2005 2004 2003
         
        Additional paid-in capital:
                                            
         Balance at beginning of year $4,028  $3,033  $3,032             
         
        Common stock issuance(a)
          1,065   970   –              
         Treasury stock reissued  18   25   1             
                           
         Balance at end of year $5,111  $4,028  $3,033             
                   
        Unearned compensation:
                                
         Balance at beginning of year $(9) $(9) $(7)            
         Changes during year  (11)  –    (2)            
                           
         Balance at end of year $(20) $(9) $(9)            
                   
        Retained earnings:
                                
         Balance at beginning of year $3,810  $2,897  $1,874             
         Net income  3,032   1,261   1,321  $3,032  $1,261  $1,321 
         Dividends paid (per share: $1.22 in 2005, $1.03 in 2004 and $0.96 in 2003)  (436)  (348)  (298)            
                           
         Balance at end of year $6,406  $3,810  $2,897             
                   
        Accumulated other comprehensive loss(b):
                                
         Minimum pension liability adjustments:                        
          Balance at beginning of year $(71) $(93) $(47)            
          Changes during year  (70)  22   (46)  (70)  22   (46)
                           
          Balance at end of year $(141) $(71) $(93)            
         Foreign currency translation adjustments:                        
          Balance at beginning of year $(5) $(4) $(1)            
          Changes during year  –    (1)  (3)  –    (1)  (3)
                           
          Balance at end of year $(5) $(5) $(4)            
         Deferred gains (losses) on derivative instruments:                        
          Balance at beginning of year $12  $(15) $(21)            
          Reclassification of the cumulative effect adjustment into income  (2)  (3)  (3)  (2)  (3)  (3)
          Changes in fair value  (15)  (82)  (50)  (15)  (82)  (50)
          Reclassification to income  –    112   59   –    112   59 
                           
          Balance at end of year $(5) $12  $(15)            
                           
           Total balances at end of year $(151) $(64) $(112)            
         
            
        Total comprehensive income
                     $2,945  $1,309  $1,278 
         
        Total stockholders’ equity
         $11,705  $8,111  $6,075             
                   
        (a)On March 31, 2004, Marathon issued 34,500,000 shares of its common stock at the offering price of $30 per share and recorded net proceeds of $1.004 billion. On June 30, 2005, in connection with the acquisition of Ashland Inc.’s minority interest in Marathon Petroleum Company LLC, Marathon distributed 17,538,815 shares of its common stock valued at $54.45 per share to Ashland’s shareholders.
        (b)Related income tax provision (credit) on changes and reclassifications during the year:
                       
          2005 2004 2003  
                 
        Minimum pension liability adjustments $(42) $3  $(25)  
        Foreign currency translation adjustments  –    –    (2)  
        Net deferred gains (losses) on derivative instruments  (3)  9   3   
        The accompanying notes are an integral part of these consolidated financial statements.

        F-7


        Notes to Consolidated Financial Statements
        1. Summary of Principal Accounting Policies
        Marathon Oil Corporation (“Marathon”) is engaged in worldwide exploration and production of crude oil and natural gas; domestic refining, marketing and transportation of crude oil and petroleum products; and worldwide marketing and transportation of natural gas and products manufactured from natural gas.
        Principles applied in consolidation – These consolidated financial statements include the accounts of the businesses comprising Marathon.
             Prior to June 30, 2005, Marathon owned a 62 percent interest in Marathon Petroleum Company LLC (“MPC”). After Marathon acquired the remaining 38 percent interest as described in Note 5, MPC became a wholly owned subsidiary of Marathon. The accounts of MPC are consolidated in these financial statements for all periods presented and the applicable minority interest has been recognized for activity prior to the acquisition date.
             Investments in variable interest entities (“VIEs”) for which Marathon is the primary beneficiary are consolidated. Equatorial Guinea LNG Holdings Limited (“EGHoldings”), in which Marathon holds a 60% interest and was formed for the purpose of constructing and operating a liquefied natural gas (“LNG”) plant, is a VIE and Marathon is its primary beneficiary. As of December 31, 2005, total expenditures of $1.116 billion related to the LNG plant, including $1.066 billion of capital expenditures, have been incurred.
             Investments in unincorporated oil and natural gas joint ventures and undivided interests in certain pipelines, natural gas processing plants and LNG tankers are consolidated on a pro rata basis.
             Investments in entities over which Marathon has significant influence, but not control, are accounted for using the equity method of accounting and are carried at Marathon’s share of net assets plus loans and advances. This includes entities in which Marathon holds majority ownership but the minority shareholders have substantive participating rights in the investee. Differences in the basis of the investment and the separate net asset value of the investee, if any, are amortized into income over the remaining useful life of the underlying assets. Income from equity method investments represents Marathon’s proportionate share of income generated by the equity method investees.
             Gains or losses from a change in ownership of a consolidated subsidiary or an unconsolidated investee are recognized in income in the period of change.
        Use of estimates – The preparation of financial statements in accordance with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the respective reporting periods.
        Income per common share – Basic net income per share is calculated based on the weighted average number of common shares outstanding. Diluted net income per share assumes exercise of stock options and warrants and conversion of convertible debt and preferred securities, provided the effect is not antidilutive.
        Segment information – Marathon’s operations consist of three reportable operating segments:
        Exploration and Production (“E&P”) – explores for and produces crude oil and natural gas on a worldwide basis;
        Refining, Marketing and Transportation (“RM&T”) – refines, markets and transports crude oil and petroleum products, primarily in the Midwest, the upper Great Plains and southeastern United States; and
        Integrated Gas (“IG”) – markets and transports natural gas and products manufactured from natural gas, such as LNG and methanol, on a worldwide basis.
             Management has determined that these are its operating segments because these are the components of Marathon (1) that engage in business activities from which revenues are earned and expenses are incurred, (2) whose operating results are regularly reviewed by Marathon’s chief operating decision maker to make decisions about resources to be allocated and to assess performance and (3) for which discrete financial information is available. The chief operating decision maker (“CODM”) is responsible for allocating resources to and assessing performance of Marathon’s operating segments. Information on assets by segment is not presented because it is not reviewed by the CODM. The CODM is the manager over the E&P and IG segments. In this role, the CODM is responsible for allocating resources within those segments, reviewing financial results of components within those segments, and assessing the performance of the components. The components within these segments that are separately reviewed and assessed by the CODM in his role as segment manager are aggregable because they have similar economic characteristics. The segment manager of the RM&T segment reports to the CODM. The RM&T segment manager is responsible for allocating resources within the segment, reviewing financial results of components within the segment, and assessing the performance of the components. The CODM reviews these financial results at the RM&T segment level.

        F-8Marathon Oil Corporation ("Marathon" or the "Company") is engaged in worldwide exploration, production and marketing of crude oil and natural gas; domestic refining, marketing and transportation of crude oil and petroleum products; and worldwide marketing and transportation of products manufactured from natural gas, such as liquefied natural gas ("LNG") and methanol, and development of other projects to link stranded natural gas resources with key demand areas.


        Principles applied in consolidation  –  These consolidated financial statements include the accounts of the businesses comprising Marathon.

                Prior to June 30, 2005, Marathon owned a 62 percent interest in Marathon Petroleum Company LLC ("MPC"). After Marathon acquired the remaining 38 percent interest as described in Note 6, MPC became a wholly owned subsidiary of Marathon. The accounts of MPC are consolidated in these financial statements for all periods presented and the applicable minority interest has been recognized for activity prior to the acquisition date.

             Segment income represents income from operations allocable to operating segments. Marathon’s corporate general and administrative costs are not allocated to operating segments. These costs primarily consist of employment costs (including pension effects), professional services, facilities and other costs associated with corporate activities. These costs also include non-cash effects of stock-based compensation for all employees except those of MPC. Non-cash effects of stock-based compensation for MPC employees are allocated to the RM&T segment. Non-cash gains and losses on two long-term natural gas sales contracts in the United Kingdom accounted for as derivative instruments, gains and losses on ownership changes in subsidiaries and certain non-operating or infrequently occurring items (as determined by the CODM) also are not allocated to operating segments. See the reconciliation of segment income to consolidated income from operations in Note 8.

        Revenue recognition – Revenues are recognized when products are shipped or services are provided to customers, the sales price is fixed or determinable and collectibility is reasonably assured. Costs associated with revenues are recorded in cost of revenues.
             Marathon recognizes revenues from the production of oil and natural gas when title is transferred. In the United States and certain international locations, production volumes of liquid hydrocarbons and natural gas are sold immediately and transported via pipeline. At other international locations, production volumes may be stored as inventory and sold at a later time. Royalties on the production of oil and natural gas are either paid in cash or settled through the delivery of volumes. Marathon includes royalties in its revenues and cost of revenues when settlement of the royalties is paid in cash, while royalties settled by the delivery of volumes are excluded from revenues and cost of revenues.
             Rebates from vendors are recognized as a reduction to cost of revenues when the initiating transaction occurs. Incentives that are derived from contractual provisions are accrued based on past experience and recognized in cost of revenues.
         ��   Marathon follows the sales method of accounting for natural gas production imbalances and would recognize a liability if the existing proved reserves were not adequate to cover the current imbalance situation.
        Matching buy/sell transactions – Marathon considers matching buy/sell transactions to be arrangements in which Marathon agrees to buy a specific quantity and quality of crude oil or refined petroleum products to be delivered at a specific location while simultaneously agreeing to sell a specified quantity and quality of crude oil or refined petroleum products at a different location, usually with the same counterparty. All matching buy/sell transactions are settled in cash and are recorded in both revenues and cost of revenues as separate sales and purchase transactions, or on a “gross”        Investments in unincorporated oil and natural gas joint ventures and undivided interests in certain pipelines, natural gas processing plants and LNG tankers are consolidated on a pro rata basis. The commodity purchased and the commodity sold generally are similar in nature.
             In a typical matching buy/sell transaction, Marathon enters into a contract to sell a particular grade of crude oil or refined product at a specified location and date to a particular counterparty, and simultaneously agrees to buy a particular grade of crude oil or refined product at a different location on the same or another specified date, typically from the same counterparty. The value of the purchased volumes rarely equals the sales value of the sold volumes. The value differences between purchases and sales are primarily due to (1) grade/ quality differentials, (2) location differentials and/or (3) timing differences in those instances when the purchase and sale do not occur in the same month.
             For the E&P segment, Marathon enters into matching buy/sell transactions to reposition crude oil from one market center to another to maximize the value received for Marathon’s crude oil production. For the RM&T segment, Marathon enters into crude oil matching buy/sell transactions to secure the most profitable refinery supply and enters into refined product matching buy/sell transactions to meet projected customer demand and to secure the required volumes in the most cost-effective manner.
             The characteristics of Marathon’s matching buy/sell transactions include gross invoicing between Marathon and its counterparties and cash settlement of the transactions. Nonperformance by one party to deliver generally does not relieve the other party’s obligation to perform. Both transactions require physical delivery of the product. The risks and rewards of ownership are evidenced by title transfer, assumption of environmental risk, transportation scheduling, credit risk, counterparty nonperformance risk and the fact that Marathon has the primary obligation to perform.
             Marathon will be required to change its accounting for purchases and sales of inventory with the same counterparty, including certain matching buy/sell transactions, in the second quarter of 2006. See Note 30 for further information.
        Cash and cash equivalents – Cash and cash equivalents include cash on hand and on deposit and investments in highly liquid debt instruments with maturities generally of three months or less.
        Inventories – Inventories are carried at lower of cost or market. Cost of inventories is determined primarily under the last-in, first-out (LIFO) method.
             An inventory market valuation reserve results when the recorded LIFO cost basis of crude oil and refined products inventories exceeds net realizable value. The reserve is decreased when market prices increase and

        F-9        Investments in variable interest entities ("VIEs") for which Marathon is the primary beneficiary are consolidated.


                Investments in entities over which Marathon has significant influence, but not control, are accounted for using the equity method of accounting and are carried at Marathon's share of net assets plus loans and advances. This includes entities in which Marathon holds majority ownership but the minority shareholders have substantive participating rights in the investee. Differences in the basis of the investments and the separate net asset values of the investees, if any, are amortized into net income over the remaining useful lives of the underlying assets, except for the excess related to goodwill. Income from equity method investments represents Marathon's proportionate share of net income generated by the equity method investees.

                Gains or losses from a change in ownership of a consolidated subsidiary or an unconsolidated investee are recognized in net income in the period of change.

        inventories turn over and is increased when market prices decrease. Changes in the inventory market valuation reserve result in non-cash charges or credits to costs and expenses.

        Accounts receivable and allowance for doubtful accounts – Marathon’s receivables primarily consist of customer accounts receivable, including proprietary credit card receivables. The allowance for doubtful accounts is the best estimate of the amount of probable credit losses in Marathon’s proprietary credit card receivables. Marathon determines the allowance based on historical write-off experience and the volume of proprietary credit card sales. Marathon reviews the allowance for doubtful accounts quarterly and past-due balances over 180 days are reviewed individually for collectibility. All other customer receivables are recorded at the invoiced amounts and generally do not bear interest. Account balances for these customer receivables are charged directly to bad debt expense when it becomes probable the receivable will not be collected.
        Traditional derivative instruments – Marathon uses derivatives to manage its exposure to commodity price risk, interest rate risk and foreign currency risk. Management has authorized the use of futures, forwards, swaps and combinations of options, including written or net written options, related to the purchase, production or sale of crude oil, natural gas and refined products, the fair value of certain assets and liabilities, future interest expense and certain business transactions denominated in foreign currencies. Changes in the fair values of all derivatives are recognized immediately in income, in revenues, other income, cost of revenues or net interest and other financing costs, unless the derivative qualifies as a hedge of future cash flows or certain foreign currency exposures. Cash flows related to derivatives used to manage commodity price risk and interest rate risk, as well as foreign currency exchange rate risk related to operating expenditures, are classified in operating activities with the underlying hedged transactions. Cash flows related to derivatives used to manage exchange rate risk related to capital expenditures denominated in foreign currencies are classified in investing activities with the underlying hedged transactions.
             For derivatives qualifying as hedges of future cash flows or certain foreign currency exposures, the effective portion of any changes in fair value is recognized in accumulated other comprehensive income, a component of stockholders’ equity, and is reclassified to income – in revenues, cost of revenues, depreciation, depletion and amortization or net interest and other financing costs – when the underlying forecasted transaction is recognized in income. Any ineffective portion of such hedges is recognized in income as it occurs. For discontinued cash flow hedges, prospective changes in the fair value of the derivative are recognized in income. Any gain or loss in accumulated other comprehensive income at the time a hedge is discontinued continues to be deferred until the original forecasted transaction occurs. However, if it is determined that the likelihood of the original forecasted transaction occurring is no longer probable, the entire related gain or loss in accumulated other comprehensive income is immediately reclassified into income.
             For derivatives designated as hedges of the fair value of recognized assets, liabilities or firm commitments, changes in the fair values of both the hedged item and the related derivative are recognized immediately in income – in revenues, cost of revenues or net interest and other financing costs – with an offsetting effect included in the basis of the hedged item. The net effect is to report in income the extent to which the hedge is not effective in achieving offsetting changes in fair value.
             As market conditions change, Marathon may use selective derivative instruments that assume market risk. For derivative instruments that are classified as trading, changes in the fair value are recognized immediately in other income. Any premium received is amortized into income based on the underlying settlement terms of the derivative position. All related effects of a trading strategy, including physical settlement of the derivative position, are recognized in other income.
        Nontraditional derivative instruments – Certain contracts involving the purchase or sale of commodities are not considered normal purchases or normal sales under generally accepted accounting principles and are required to be accounted for as derivative instruments. Marathon refers to such contracts as “nontraditional derivative instruments” because, unlike traditional derivative instruments, nontraditional derivative instruments have not been entered into to manage a risk exposure. Such contracts are recorded in the balance sheet at fair value and changes in fair values are recognized in income as revenues or cost of revenues.
             In the E&P segment, two long-term natural gas delivery commitment contracts in the United Kingdom are classified as nontraditional derivative instruments. These contracts contain pricing provisions that are not clearly and closely related to the underlying commodity and therefore must be accounted for as derivative instruments.
             In the RM&T segment, certain physical commodity contracts are classified as nontraditional derivative instruments because certain volumes under these contracts are physically netted at particular delivery locations. The netting process causes all contracts at that delivery location to be considered derivative instruments. Other physical contracts that involve flash title are also accounted for as nontraditional derivative instruments as Marathon has not elected to treat these contracts as normal purchases or normal sales.
        Property, plant and equipment – Marathon uses the successful efforts method of accounting for oil and gas producing activities. Costs to acquire mineral interests in oil and natural gas properties, to drill and equip exploratory wells that find proved reserves, and to drill and equip development wells are capitalized. Costs to drill
        Use of estimates  –  The preparation of financial statements in accordance with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the respective reporting periods.

        F-10Income per common share  –  Basic income per share is calculated based on the weighted average number of common shares outstanding. Diluted income per share assumes exercise of stock options and warrants and conversion of convertible debt and preferred securities, provided the effect is not antidilutive.


        Segment information  –  Marathon's operations consist of three reportable operating segments:

        Exploration and Production ("E&P") – explores for, produces and markets crude oil and natural gas on a worldwide basis;
        Refining, Marketing and Transportation ("RM&T") – refines, markets and transports crude oil and petroleum products, primarily in the Midwest, the upper Great Plains and southeastern United States; and
        Integrated Gas ("IG") – markets and transports products manufactured from natural gas, such as LNG and methanol, on a worldwide basis, and is developing other projects to link stranded natural gas resources with key demand areas.

                Management has determined that these are its operating segments because these are the components of Marathon (1) that engage in business activities from which revenues are earned and expenses are incurred, (2) whose operating results are regularly reviewed by Marathon's chief operating decision maker ("CODM") to make decisions about resources to be allocated and to assess performance and (3) for which discrete financial information is available. The CODM is responsible for allocating resources to and assessing performance of Marathon's operating segments. Information regarding assets by segment is not presented because it is not reviewed by the CODM. The CODM is the manager over the E&P and IG segments and the manager of the RM&T segment reports to the CODM. The segment managers are responsible for allocating resources within the segments, reviewing financial results of components within the segments and assessing the performance of the components. The components within the segments that are separately reviewed and assessed by the CODM in his role as segment manager are aggregable because they have similar economic characteristics. The CODM reviews the financial results of the RM&T segment at the segment level.

                Segment income represents income from continuing operations, net of minority interests and income taxes, attributable to the operating segments. Marathon's corporate general and administrative costs are not allocated to the operating segments. These costs primarily consist of employment costs (including pension effects), professional services, facilities and other costs associated with corporate activities. Non-cash gains and losses on two long-term natural gas sales contracts in the United Kingdom accounted for as derivative instruments, gains and losses on ownership changes in subsidiaries and certain non-operating or infrequently occurring items (as determined by the CODM) also are not allocated to operating segments. See the reconciliation of segment income to consolidated net income in Note 9.

        exploratory wells that do not find proved reserves, geological and geophysical costs, and costs of carrying and retaining unproved properties are expensed. Costs incurred for exploratory wells that find reserves that cannot yet be classified as proved are capitalized if (1) the well has found a sufficient quantity of reserves to justify its completion as a producing well and (2) Marathon is making sufficient progress assessing the reserves and the economic and operating viability of the project. The status of suspended well costs is monitored continuously and reviewed not less than quarterly.
             Capitalized costs of producing oil and natural gas properties are depreciated and depleted by the units-of-production method. Support equipment and other property, plant and equipment are depreciated on a straight line basis over their estimated useful lives.
             Marathon evaluates its oil and gas producing properties for impairment of value on a field-by-field basis or, in certain instances, by logical grouping of assets if there is significant shared infrastructure. Impairment of proved properties is required when carrying value exceeds undiscounted future net cash flows based on total proved and risk-adjusted probable and possible reserves. Oil and gas producing properties deemed to be impaired are written down to their fair value, as determined by discounted future net cash flows based on total proved and risk-adjusted probable and possible reserves or, if available, comparable market values.
             Marathon evaluates its unproved property investment and impairs based on time or geologic factors in addition to the use of an undiscounted future net cash flow approach. Information such as drilling results, reservoir performance, seismic interpretation or future plans to develop acreage are also considered. Unproved property investments deemed to be impaired are written down to their fair value, as determined by discounted future net cash flows. Impairment expense for unproved oil and natural gas properties is reported in exploration expenses.
             Property, plant and equipment unrelated to oil and gas producing activities is recorded at cost and depreciated on the straight-line method over the estimated useful lives of the assets, which range from 3 to 42 years. Such assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If the sum of the expected future cash flows from the use of the asset and its eventual disposition is less than the carrying amount of the asset, an impairment loss is recognized based on the fair value of the asset.
             When property, plant and equipment depreciated on an individual basis are sold or otherwise disposed of, any gains or losses are reported in income. Gains on disposal of property, plant and equipment are recognized when earned, which is generally at the time of closing. If a loss on disposal is expected, such losses are recognized when the assets are classified as held for sale. Proceeds from disposal of property, plant and equipment depreciated on a group basis are credited to accumulated depreciation, depletion and amortization with no immediate effect on income.

        Goodwill – Goodwill represents the excess of the purchase price over the estimated fair value of the net assets acquired in the acquisition of a business. Such goodwill is not amortized, but rather is tested for impairment annually and when events or changes in circumstances indicate that the fair value of a reporting unit with goodwill has been reduced below carrying value. The impairment test requires allocating goodwill and other assets and liabilities to reporting units. Marathon has determined the components of the E&P segment have similar economic characteristics and therefore aggregates the components into a single reporting unit. The RM&T segment is composed of three reporting units: refining and marketing, pipeline transportation and retail marketing. The fair value of each reporting unit is determined and compared to the book value of the reporting unit. If the fair value of the reporting unit is less than the book value, including goodwill, then the recorded goodwill is impaired to its implied fair value with a charge to expense.
        Intangible assets – Intangible assets primarily include retail marketing tradenames, intangible contract rights and marketing branding agreements. Certain of the marketing tradenames have indefinite lives and therefore are not amortized, but rather are tested for impairment annually and when events or changes in circumstances indicate that the fair value of the intangible asset has been reduced below carrying value. The other intangible assets are amortized over their estimated useful lives or the expected lives of the related contracts, as applicable, which range from 2 to 22 years. Such assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If the sum of the expected future cash flows from the use of the asset and its eventual disposition is less than the carrying amount of the asset, an impairment loss is recognized based on the fair value of the asset.
        Major maintenance activities – Marathon incurs costs for planned major refinery maintenance (“turnarounds”). Such costs are expensed in the same annual period as incurred; however, estimated annual turnaround costs are recognized as expense throughout the year on a pro rata basis.
        Environmental remediation liabilities – Environmental remediation expenditures are capitalized if the costs mitigate past or prevent future contamination or if the costs improve environmental safety or efficiency of the existing assets. Marathon provides for remediation costs and penalties when the responsibility to remediate is probable and the amount of associated costs can be reasonably estimated. The timing of remediation accruals coincides with completion of a feasibility study or the commitment to a formal plan of action. Remediation liabilities
        Revenue recognition  –  Revenues are recognized when products are shipped or services are provided to customers, title is transferred, the sales price is fixed or determinable and collectibility is reasonably assured. Costs associated with revenues are recorded in cost of revenues.

        F-11F-8


                Marathon recognizes revenues from the production of oil and natural gas when title is transferred. In the continental United States, production volumes of liquid hydrocarbons and natural gas are sold immediately and transported via pipeline. In Alaska and international locations, production volumes may be stored as inventory and sold at a later time. Royalties on the production of oil and natural gas are either paid in cash or settled through the delivery of volumes. Marathon includes royalties in its revenues and cost of revenues when settlement of the royalties is paid in cash, while royalties settled by the delivery of volumes are excluded from revenues and cost of revenues.


                Rebates from vendors are recognized as a reduction of cost of revenues when the initiating transaction occurs. Incentives that are derived from contractual provisions are accrued based on past experience and recognized in cost of revenues.

                Marathon follows the sales method of accounting for crude oil and natural gas production imbalances and would recognize a liability if the existing proved reserves were not adequate to cover the current imbalance situation.

        are accrued based on estimates of known environmental exposure and are discounted when the estimated amounts are reasonably fixed and determinable. If recoveries of remediation costs from third parties are probable, a receivable is recorded and is discounted when the estimated amount is reasonably fixed and determinable.
        Asset retirement obligations – The fair values of asset retirement obligations are recognized in the period in which they are incurred if a reasonable estimate of fair value can be made. For Marathon, asset retirement obligations primarily relate to the abandonment of oil and gas producing facilities. Asset retirement obligations for such facilities include costs to dismantle and relocate or dispose of production platforms, gathering systems, wells and related structures and restoration costs of land and seabed, including those leased. Estimates of these costs are developed for each property based on the type of production structure, depth of water, reservoir characteristics, depth of the reservoir, market demand for equipment, currently available procedures and consultations with construction and engineering professionals. Asset retirement obligations have not been recognized for certain of Marathon’s international oil and gas producing facilities as Marathon currently does not have a legal obligation associated with the retirement of those facilities.
             Asset retirement obligations have not been recognized for the removal of materials and equipment from or the closure of certain refinery, pipeline and marketing assets because the fair value cannot be reasonably estimated due to an indeterminate settlement date of the obligation. Upon adoption of Financial Accounting Standards Board (“FASB”) Interpretation (“FIN”) No. 47, “Accounting for Conditional Asset Retirement Obligations – an interpretation of FASB Statement No. 143,” on December 31, 2005, conditional asset retirement obligations for removal and disposal of fire-retardant material from certain refining facilities were recognized based on the most probable current cost projections. See Note 2 for further information regarding Marathon’s adoption of FIN No. 47.
             Current inflation rates and credit-adjusted-risk-free interest rates are used to estimate the fair values of asset retirement obligations. Depreciation of capitalized asset retirement costs and accretion of asset retirement obligations are recorded over time. The depreciation will generally be determined on a units-of-production basis for production facilities and on a straight-line basis for refining facilities, while the accretion to be recognized will escalate over the lives of the assets.

        Deferred taxes – Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of assets and liabilities and their tax bases as reported in Marathon’s filings with the respective taxing authorities. The realization of deferred tax assets is assessed periodically based on several interrelated factors. These factors include Marathon’s expectation to generate sufficient future taxable income including future foreign source income, tax credits, operating loss carryforwards, and management’s intent regarding the permanent reinvestment of the income from certain foreign subsidiaries.
        Pensions and other postretirement benefits – Marathon has noncontributory defined benefit pension plans covering substantially all domestic employees as well as international employees located in Ireland, Norway and the United Kingdom. In addition, several excess benefits plans exist covering domestic employees within defined regulatory compensation limits. Benefits under these plans are based primarily on years of service and final average pensionable earnings. The benefits provided include both pension and health care.
             Marathon also has defined benefit plans for other postretirement benefits covering most employees. Health care benefits are provided through comprehensive hospital, surgical and major medical benefit provisions subject to various cost sharing features. Life insurance benefits are provided to certain nonunion and union represented retiree beneficiaries. Other postretirement benefits have not been funded in advance.
             Marathon uses a December 31 measurement date for its pension and other postretirement benefit plans.
        Stock-based compensation – The Marathon Oil Corporation 2003 Incentive Compensation Plan (the “Plan”) authorizes the Compensation Committee of the Board of Directors of Marathon to grant stock options, stock appreciation rights, stock awards, cash awards and performance awards to employees. The Plan also allows Marathon to provide equity compensation to its non-employee directors. No more than 20,000,000 shares of common stock may be issued under the Plan, and no more than 8,500,000 of those shares may be used for awards other than stock options or stock appreciation rights. Shares subject to awards that are forfeited, terminated, expire unexercised, settled in cash, exchanged for other awards, tendered to satisfy the purchase price of an award, withheld to satisfy tax obligations or otherwise lapse become available for future grants.
             The Plan replaced the 1990 Stock Plan, the Non-Officer Restricted Stock Plan, the Non-Employee Director Stock Plan, the deferred stock benefit provision of the Deferred Compensation Plan for Non-Employee Directors, the Senior Executive Officer Annual Incentive Compensation Plan, and the Annual Incentive Compensation Plan (collectively, the “Prior Plans”). No new grants will be made from the Prior Plans. Any awards previously granted under the Prior Plans shall continue to vest and/or be exercisable in accordance with their original terms and conditions.
             Marathon’s stock options represent the right to purchase shares of common stock at the fair market value of the common stock on the date of grant. Prior to 2004, certain options were granted with a tandem stock appreciation right, which allows the recipient to instead elect to receive cash and/or common stock equal to the excess of the fair
        Matching buy/sell transactions  –  In a typical matching buy/sell transaction, Marathon enters into a contract to sell a particular quantity and quality of crude oil or refined product at a specified location and date to a particular counterparty, and simultaneously agrees to buy a particular quantity and quality of the same commodity at a specified location on the same or another specified date from the same counterparty. The value of the purchased volumes rarely equals the sales value of the sold volumes. The value differences between purchases and sales are primarily due to (1) grade/quality differentials, (2) location differentials and/or (3) timing differences in those instances when the purchase and sale do not occur in the same month.

        F-12        For the E&P segment, Marathon enters into matching buy/sell transactions to reposition crude oil from one market center to another to maximize the value received for Marathon's crude oil production. For the RM&T segment, Marathon enters into crude oil matching buy/sell transactions to secure the most profitable refinery supply and enters into refined product matching buy/sell transactions to meet projected customer demand and to secure the required volumes in the most cost-effective manner.


                Prior to April 1, 2006, Marathon recorded all such matching buy/sell transactions in both revenues and cost of revenues as separate sale and purchase transactions. Effective April 1, 2006, upon adoption of the provisions of Emerging Issues Task Force ("EITF") Issue No. 04-13, Marathon accounts for matching buy/sell arrangements entered into or modified as exchanges of inventory, except for those arrangements accounted for as derivative instruments.

                A portion of Marathon's matching buy/sell transactions are "nontraditional derivative instruments," which are described below. Effective for contracts entered into or modified on or after April 1, 2006, the income effects of matching buy/sell arrangements accounted for as nontraditional derivative instruments are recognized on a net basis as cost of revenues.

        market value of shares of common stock, as determined in accordance with the Plan, over the option price of the shares. Most stock options granted under the Plan vest ratably over a three-year period and all expire ten years from the date they are granted.
             Similar to stock options, stock appreciation rights (“SARs”) represent the right to receive a payment equal to the excess of the fair market value of shares of common stock on the date the right is exercised over the exercise price. In general, SARs that have been granted under the Plan are settled in shares of stock, vest ratably over a three-year period and have a maximum term of ten years from the date they are granted.
             In 2003 and 2004, the Compensation Committee granted stock-based Performance Awards to Marathon’s officers under the Plan. The stock-based Performance Awards represent shares of common stock that are subject to forfeiture provisions and restrictions on transfer. Those restrictions may be removed if certain pre-established performance measures are met. The stock-based Performance Awards granted under the Plan generally vest at the end of a 36-month performance period if certain pre-established performance targets are achieved and the recipient remains employed by Marathon at that date.
             In 2005, the Compensation Committee granted cash-based Performance Awards to Marathon’s and MPC’s officers under the Plan. The cash-based performance units generally vest at the end of a 36-month performance period if certain pre-established performance targets are achieved and the recipient remains employed by Marathon at that date. The target value of each performance unit granted is $1, with the actual payout varying from zero percent to 200 percent of the target value based on actual performance achieved. The Compensation Committee also granted time-based restricted stock to the officers under the Plan in 2005. The restricted stock awards vest three years from the date of grant, contingent on the recipient’s continued employment. Prior to vesting, the restricted stock recipients have the right to vote such stock and receive dividends thereon. The nonvested shares are not transferable and are retained by Marathon until they vest.
             Marathon also grants restricted stock to certain non-officer employees under the Plan based on their performance within certain guidelines and for retention purposes. The restricted stock awards generally vest in one-third increments over a three-year period, contingent on the recipient’s continued employment. Prior to vesting, the restricted stock recipients have the right to vote such stock and receive dividends thereon. The nonvested shares are not transferable and are retained by Marathon until they vest.
             Unearned compensation is charged to stockholders’ equity when restricted stock and performance shares are granted. Compensation expense is recognized over the balance of the vesting period and is adjusted if conditions of the restricted stock or performance share grant are not met. Cash-based performance units are classified as a liability and compensation expense is recognized over the 36-month performance period based on expected payout.
             Marathon maintains an equity compensation program for its non-employee directors under the Plan. Pursuant to the program, non-employee directors must defer 50 percent of their annual retainers in the form of common stock units. In addition, each non-employee director receives an annual grant of non-retainer common stock units under the Plan. In 2005, the value of each grant was $60,000. The program also provides each non-employee director with a matching grant of up to 1,000 shares of common stock on his or her initial election to the Board if he or she purchases an equivalent number of shares within 60 days of joining the Board.
             Effective January 1, 2003, Marathon has applied the fair value based method of accounting to all grants and any modified grants of stock-based compensation. All prior outstanding and unvested awards continue to be accounted for under the intrinsic value method. The following net income and per share data illustrates the effect on net income and net income per share if the fair value method had been applied to all outstanding and unvested awards in each period.

                      
        (In millions, except per share data) 2005 2004 2003
         
        Net income:            
         As reported $3,032  $1,261  $1,321 
         Add: Stock-based employee compensation expense included in reported net income, net of related tax effects  72   39   23 
         Deduct: Total stock-based employee compensation expense determined under the fair value method for all awards, net of related tax effects  (72)  (32)  (17)
                  
        Pro forma net income $3,032  $1,268  $1,327 
                  
        Basic net income per share:            
         – As reported $8.52  $3.75  $4.26 
         – Pro forma $8.52  $3.77  $4.28 
        Diluted net income per share:            
         – As reported $8.44  $3.73  $4.26 
         – Pro forma $8.44  $3.75  $4.28 
         
                See Note 2 for further information regarding Marathon's adoption of EITF Issue No. 04-13.

        F-13Consumer excise taxes  –  Marathon is required by various governmental authorities, including countries, states and municipalities, to collect and remit taxes on certain consumer products. Such taxes are presented on a gross basis in revenues and costs and expenses in the consolidated statements of income.


        Cash and cash equivalents  –  Cash and cash equivalents include cash on hand and on deposit and investments in highly liquid debt instruments with maturities generally of three months or less.

        Accounts receivable and allowance for doubtful accounts  –  Marathon's receivables primarily consist of customer accounts receivable, including proprietary credit card receivables. The allowance for doubtful accounts is the best estimate of the amount of probable credit losses in Marathon's proprietary credit card receivables. Marathon determines the allowance based on historical write-off experience and the volume of proprietary credit card sales. Marathon reviews the allowance quarterly and past-due balances over 180 days are reviewed individually for collectibility.    All other customer receivables are recorded at the invoiced amounts and generally do not bear interest. Account balances for these customer receivables are charged directly to bad debt expense when it becomes probable the receivable will not be collected.

             Marathon records compensation cost over the stated vesting period for stock options that are subject to specific vesting conditions and specify (1) that an employee vests in the award upon becoming “retirement eligible” or (2) that the employee will continue to vest in the award after retirement without providing any additional service. Upon adoption of Statement of Financial Accounting Standards (“SFAS”) No. 123 (Revised 2004), “Share-Based Payment,” such compensation cost will be recognized immediately for awards granted to retirement-eligible employees or over the period from the grant date to the retirement eligibility date if retirement eligibility will be reached during the stated vesting period. The compensation cost determined under these two approaches did not differ materially for the periods presented above.
             The above pro forma amounts were based on a Black-Scholes option-pricing model, which included the following information and assumptions:
                     
          2005 2004 2003
         
        Weighted-average grant-date exercise price per share $50.28  $33.61  $25.58 
        Expected annual dividends per share $1.32  $1.00  $0.97 
        Expected life in years  5.5   5.5   5.0 
        Expected volatility  28%  32%  34%
        Risk-free interest rate  3.8%  3.9%  3.0%
         
        Weighted-average grant-date fair value of options granted during the year, as calculated from above $12.30  $8.83  $5.37 
         
        Concentrations of credit risk – Marathon is exposed to credit risk in the event of nonpayment by counterparties, a significant portion of which are concentrated in energy related industries. The creditworthiness of customers and other counterparties is subject to continuing review, including the use of master netting agreements, where appropriate. While no single customer accounts for more than 10 percent of annual revenues, Marathon has significant exposures to United States Steel arising from the Separation. These exposures are discussed in Note 3.
        Reclassifications – Certain reclassifications of prior years’ data have been made to conform to 2005 classifications.
        Inventories  –  Inventories are carried at the lower of cost or market value. Cost of inventories is determined primarily under the last-in, first-out ("LIFO") method. An inventory market valuation reserve results when the recorded LIFO cost basis of crude oil and refined products inventories exceeds net realizable value. The reserve is decreased when market prices increase and inventories turn over and is increased when market prices decrease. Changes in the inventory market valuation reserve result in non-cash charges or credits to costs and expenses.

        Traditional derivative instruments  –  Marathon uses derivatives to manage its exposure to commodity price risk, interest rate risk and foreign currency risk.    Management has authorized the use of futures, forwards, swaps and combinations of options, including written or net written options, related to the purchase, production or sale of crude oil, natural gas, refined products and ethanol, the fair value of certain assets and liabilities, future interest expense and certain business transactions denominated in foreign currencies. Changes in the fair values of all traditional derivatives are recognized immediately in net income unless the derivative qualifies as a hedge of future cash flows or certain foreign currency exposures. Cash flows related to derivatives used to manage commodity price risk, interest rate risk and foreign currency exchange rate risk related to operating expenditures are classified in operating activities with the underlying hedged transactions. Cash flows related to derivatives used to manage exchange rate risk related to capital expenditures denominated in foreign currencies are classified in investing activities with the underlying hedged transactions.

                For derivatives qualifying as hedges of future cash flows or certain foreign currency exposures, the effective portion of any changes in fair value is recognized in other comprehensive income and is reclassified to net income when the

        F-9


        underlying forecasted transaction is recognized in net income. Any ineffective portion of such hedges is recognized in net income as it occurs. For discontinued cash flow hedges, prospective changes in the fair value of the derivative are recognized in net income. The accumulated gain or loss recognized in other comprehensive income at the time a hedge is discontinued continues to be deferred until the original forecasted transaction occurs. However, if it is determined that the likelihood of the original forecasted transaction occurring is no longer probable, the entire accumulated gain or loss recognized in other comprehensive income is immediately reclassified into net income.

                For derivatives designated as hedges of the fair value of recognized assets, liabilities or firm commitments, changes in the fair values of both the hedged item and the related derivative are recognized immediately in net income with an offsetting effect included in the basis of the hedged item. The net effect is to report in net income the extent to which the hedge is not effective in achieving offsetting changes in fair value.

                Amounts reported in net income are classified as revenues, cost of revenues, depreciation, depletion and amortization or net interest and other financing costs or income based on the nature of the underlying transactions.

                As market conditions change, Marathon may use selective derivative instruments that assume market risk. For derivative instruments that are classified as trading, changes in fair value are recognized immediately in net income and are classified as other income. Any premium received is amortized into net income based on the underlying settlement terms of the derivative position. All related effects of a trading strategy, including physical settlement of the derivative position, are also recognized in net income and classified as other income.

        Nontraditional derivative instruments  –  Certain contracts involving the purchase or sale of commodities are not considered normal purchases or normal sales under generally accepted accounting principles and are required to be accounted for as derivative instruments. Marathon refers to such contracts as "nontraditional derivative instruments" because, unlike traditional derivative instruments, nontraditional derivative instruments have not been entered into to manage a risk exposure. Such contracts are recorded on the balance sheet at fair value and changes in fair values are recognized in net income and are classified as either revenues or cost of revenues.

                In the E&P segment, two long-term natural gas delivery commitment contracts in the United Kingdom are classified as nontraditional derivative instruments. These contracts contain pricing provisions that are not clearly and closely related to the underlying commodity and therefore must be accounted for as derivative instruments.

                In the RM&T segment, certain physical commodity contracts are classified as nontraditional derivative instruments because certain volumes under these contracts are physically netted at particular delivery locations. The netting process causes all contracts at that delivery location to be considered derivative instruments. Other physical contracts that management has chosen not to designate as a normal purchase or normal sale, which can include contracts that involve flash title, are also accounted for as nontraditional derivative instruments.

        Investment in marketable securities  –  Management determines the appropriate classification of investments in marketable debt and equity securities at the time of acquisition and re-evaluates such designation as of each subsequent balance sheet date. Securities classified as "available for sale" are carried at estimated fair value with unrealized gains and losses, net of tax, recorded as a component of accumulated other comprehensive loss. Marathon holds no securities classified as "held to maturity securities" or "trading securities." Realized and unrealized gains and losses are calculated using the specific identification method.

        Property, plant and equipment  –  Marathon uses the successful efforts method of accounting for oil and gas producing activities. Costs to acquire mineral interests in oil and natural gas properties, to drill and equip exploratory wells that find proved reserves and to drill and equip development wells are capitalized. Costs to drill exploratory wells that do not find proved reserves, geological and geophysical costs and costs of carrying and retaining unproved properties are expensed. Costs incurred for exploratory wells that find reserves that cannot yet be classified as proved are capitalized if (1) the well has found a sufficient quantity of reserves to justify its completion as a producing well and (2) Marathon is making sufficient progress assessing the reserves and the economic and operating viability of the project. The status of suspended well costs is monitored continuously and reviewed not less than quarterly.

                Capitalized costs of producing oil and natural gas properties are depreciated and depleted by the units-of-production method. Support equipment and other property, plant and equipment are depreciated on a straight line basis over their estimated useful lives.

                Marathon evaluates its oil and gas producing properties for impairment of value on a field-by-field basis or, in certain instances, by logical grouping of assets if there is significant shared infrastructure. Impairment of proved properties is required when the carrying value exceeds undiscounted future net cash flows based on total proved and risk-adjusted probable and possible reserves. Oil and gas producing properties deemed to be impaired are written down to their fair value, as determined by discounted future net cash flows based on total proved and risk-adjusted probable and possible reserves or, if available, comparable market values.

                Marathon evaluates its unproved property investment and impairs based on time or geologic factors in addition to the use of an undiscounted future net cash flow approach. Information such as drilling results, reservoir performance, seismic interpretation or future plans to develop acreage are also considered. Unproved property investments deemed to be impaired are written down to their fair value, as determined by discounted future net cash flows. Impairment expense for unproved oil and natural gas properties is reported in exploration expenses.

                Property, plant and equipment unrelated to oil and gas producing activities is recorded at cost and depreciated on the straight-line method over the estimated useful lives of the assets, which range from 3 to 42 years. Such assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If the sum of the expected future cash flows from the use of the asset and its eventual disposition is less than the carrying amount of the asset, an impairment loss is recognized based on the fair value of the asset.

        F-10


                When property, plant and equipment depreciated on an individual basis are sold or otherwise disposed of, any gains or losses are reported in net income. Gains on disposal of property, plant and equipment are recognized when earned, which is generally at the time of closing. If a loss on disposal is expected, such losses are recognized when the assets are classified as held for sale. Proceeds from disposal of property, plant and equipment depreciated on a group basis are credited to accumulated depreciation, depletion and amortization with no immediate effect on net income.

        Goodwill  –  Goodwill represents the excess of the purchase price over the estimated fair value of the net assets acquired in the acquisition of a business. Such goodwill is not amortized, but rather is tested for impairment annually and when events or changes in circumstances indicate that the fair value of a reporting unit with goodwill has been reduced below carrying value. The impairment test requires allocating goodwill and other assets and liabilities to reporting units. Marathon has determined the components of the E&P segment have similar economic characteristics and therefore aggregates the components into a single reporting unit. The RM&T segment is composed of three reporting units: refining and marketing, pipeline transportation and retail marketing. The fair value of each reporting unit is determined and compared to the book value of the reporting unit. If the fair value of the reporting unit is less than the book value, including goodwill, then the recorded goodwill is impaired to its implied fair value with a charge to expense.

        Intangible assets  –  Intangible assets primarily include retail marketing tradenames, intangible contract rights and marketing branding agreements. Certain of the marketing tradenames have indefinite lives and therefore are not amortized, but rather are tested for impairment annually and when events or changes in circumstances indicate that the fair value of the intangible asset has been reduced below carrying value. The other intangible assets are amortized over their estimated useful lives or the expected lives of the related contracts, as applicable, which range from 2 to 22 years. Such assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If the sum of the expected future cash flows from the use of the asset and its eventual disposition is less than the carrying amount of the asset, an impairment loss is recognized based on the fair value of the asset.

        Environmental costs  –  Environmental expenditures are capitalized if the costs mitigate or prevent future contamination or if the costs improve environmental safety or efficiency of the existing assets. Marathon provides for remediation costs and penalties when the responsibility to remediate is probable and the amount of associated costs can be reasonably estimated. The timing of remediation accruals coincides with completion of a feasibility study or the commitment to a formal plan of action. Remediation liabilities are accrued based on estimates of known environmental exposure and are discounted when the estimated amounts are reasonably fixed and determinable. If recoveries of remediation costs from third parties are probable, a receivable is recorded and is discounted when the estimated amount is reasonably fixed and determinable.

        Asset retirement obligations  –  The fair values of asset retirement obligations are recognized in the period in which they are incurred if a reasonable estimate of fair value can be made. For Marathon, asset retirement obligations primarily relate to the abandonment of oil and gas producing facilities. Asset retirement obligations for such facilities include costs to dismantle and relocate or dispose of production platforms, gathering systems, wells and related structures and restoration costs of land and seabed, including those leased. Estimates of these costs are developed for each property based on the type of production structure, depth of water, reservoir characteristics, depth of the reservoir, market demand for equipment, currently available procedures and consultations with construction and engineering professionals. Asset retirement obligations have not been recognized for certain of Marathon's international oil and gas producing facilities as Marathon currently does not have a legal obligation associated with the retirement of those facilities.

                Effective December 31, 2005, conditional asset retirement obligations for removal and disposal of fire-retardant material from certain refining facilities have been recognized. The amounts recorded for such obligations are based on the most probable current cost projections. Asset retirement obligations have not been recognized for the removal of materials and equipment from or the closure of certain refinery, pipeline and marketing assets because the fair value cannot be reasonably estimated due to an indeterminate settlement date of the obligation.

                Current inflation rates and credit-adjusted-risk-free interest rates are used to estimate the fair values of asset retirement obligations. Depreciation of capitalized asset retirement costs and accretion of asset retirement obligations are recorded over time. Depreciation is generally determined on a units-of-production basis for oil and gas production facilities and on a straight-line basis for refining facilities, while accretion escalates over the lives of the assets.

        Deferred taxes  –  Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of assets and liabilities and their tax bases as reported in Marathon's filings with the respective taxing authorities. The realization of deferred tax assets is assessed periodically based on several interrelated factors. These factors include Marathon's expectation to generate sufficient future taxable income including future foreign source income, tax credits, operating loss carryforwards and management's intent regarding the permanent reinvestment of the income from certain foreign subsidiaries.

        Pensions and other postretirement benefits  –  Marathon uses a December 31 measurement date for its pension and other postretirement benefit plans.

        Stock-based compensation arrangements  –  Marathon adopted Statement of Financial Accounting Standards ("SFAS") No. 123(R), "Share-Based Payment," as a revision of SFAS No. 123, "Accounting for Stock-Based Compensation," as of January 1, 2006. Marathon had previously adopted the fair value method under SFAS No. 123 for grants made, modified or settled on or after January 1, 2003.

        F-11


                The fair value of stock options, stock options with tandem stock appreciation rights ("SARs") and stock-settled SARs ("stock option awards") is estimated on the date of grant using the Black-Scholes option pricing model. The model employs various assumptions, based on management's best estimates at the time of grant, which impact the fair value calculated and ultimately, the expense that is recognized over the life of the stock option award. Of the required assumptions, the expected life of the stock option award and the expected volatility of Marathon's stock price have the most significant impact on the fair value calculation. Marathon has utilized historical data and analyzed current information which reasonably support these assumptions.

                The fair value of Marathon's restricted stock awards and common stock units is determined based on the fair market value of the Company's common stock on the date of grant. Prior to adoption of SFAS No. 123 (Revised 2004), "Share-Based Payment," ("SFAS No. 123(R)") on January 1, 2006, the fair values of Marathon's stock-based performance awards were determined in the same manner as restricted stock awards. Under SFAS No. 123(R), on a prospective basis, these awards are required to be valued utilizing an option pricing model. See Note 2 for further information regarding Marathon's adoption of SFAS No. 123(R). No stock-based performance awards have been granted since May 2004.

                Effective January 1, 2006, Marathon's stock-based compensation expense is recognized based on management's best estimate of the awards that are expected to vest, using the straight-line attribution method for all service-based awards with a graded vesting feature. If actual forfeiture results are different than expected, adjustments to recognized compensation expense may be required in future periods. Unearned stock-based compensation is charged to stockholders' equity when restricted stock awards and stock-based performance awards are granted. Compensation expense is recognized over the balance of the vesting period and is adjusted if conditions of the restricted stock award or stock-based performance award are not met. Options with tandem SARs are classified as a liability and are remeasured at fair value each reporting period until settlement.

                Prior to January 1, 2006, Marathon recorded stock-based compensation expense over the stated vesting period for stock option awards that are subject to specific vesting conditions and specify (1) that an employee vests in the award upon becoming "retirement eligible" or (2) that the employee will continue to vest in the award after retirement without providing any additional service. Under SFAS No. 123(R), from the January 1, 2006 date of adoption, such compensation cost is recognized immediately for awards granted to retirement-eligible employees or over the period from the grant date to the retirement eligibility date if retirement eligibility will be reached during the stated vesting period. See Note 26 for more information on stock-based compensation expense, stock option award, stock-based performance award and restricted stock award activity, valuation assumptions and other information required to be disclosed under SFAS No. 123(R).

        Concentrations of credit risk  –  Marathon is exposed to credit risk in the event of nonpayment by counterparties, a significant portion of which are concentrated in energy-related industries. The creditworthiness of customers and other counterparties is subject to continuing review, including the use of master netting agreements, where appropriate. While no single customer accounts for more than 10 percent of annual revenues, Marathon has significant exposures to United States Steel arising from the transaction discussed in Note 3.

        Reclassifications  –  Certain reclassifications of prior years' data have been made to conform to 2006 classifications.


        2. New Accounting Standards

        In March 2005, the FASB issued FIN No. 47, “Accounting for Conditional Asset Retirement Obligations – an interpretation of FASB Statement No. 143.” This interpretation clarifies that an entity is required to recognize a liability for a legal obligation to perform asset retirement activities when the retirement is conditional on a future event if the liability’s fair value can be reasonably estimated. If the liability’s fair value cannot be reasonably estimated, then the entity must disclose (1) a description of the obligation, (2) the fact that a liability has not been recognized because the fair value cannot be reasonably estimated, and (3) the reasons why the fair value cannot be reasonably estimated. FIN No. 47 also clarifies when an entity would have sufficient information to reasonably estimate the fair value of an asset retirement obligation. Marathon adopted FIN No. 47 as of December 31, 2005. A charge of $19 million, net of taxes of $12 million, related to adopting FIN No. 47 was recognized as a cumulative effect of a change in accounting principle in 2005. At the time of adoption, total assets increased $22 million and total liabilities increased $41 million.
             The pro forma net income and net income per share effect as if FIN No. 47 had been applied during 2005, 2004 and 2003 is not significantly different than amounts reported. The following summarizes the total amount of the liability for asset retirement obligations as if FIN No. 47 had been applied during all periods presented. The pro forma impact of the adoption of FIN No. 47 on these unaudited pro forma liability amounts has been measured using the information, assumptions and interest rates used to measure the obligation recognized upon adoption of FIN No. 47.
             
        (In millions)  
         
        January 1, 2003 $384 
        December 31, 2003  438 
        December 31, 2004  527 
        December 31, 2005  711 
         
             In December 2004, the FASB issued SFAS No. 153, “Exchanges of Nonmonetary Assets – an amendment of APB Opinion No. 29.” This amendment eliminates the Accounting Principles Board (“APB”) Opinion No. 29 exception for fair value recognition of nonmonetary exchanges of similar productive assets and replaces it with an exception for exchanges of nonmonetary assets that do not have commercial substance. Marathon adopted SFAS No. 153 on a prospective basis as of July 1, 2005.
             Effective January 1, 2005, Marathon adopted FASB Staff Position (“FSP”) No. FAS 19-1, “Accounting for Suspended Well Costs,” which amended the guidance for suspended exploratory well costs in SFAS No. 19, “Financial Accounting and Reporting by Oil and Gas Producing Companies.” SFAS No. 19 requires costs of drilling exploratory wells to be capitalized pending determination of whether the well has found proved reserves. When a

        F-14SFAS No. 158  –  In September 2006, the Financial Accounting Standards Board ("FASB") issued SFAS No. 158, "Employers' Accounting for Defined Benefit Pension and Other Postretirement Plans – An Amendment of FASB Statements No. 87, 88, 106, and 132(R)." This standard requires an employer to: (1) recognize in its statement of financial position an asset for a plan's overfunded status or a liability for a plan's underfunded status; (2) measure a plan's assets and its obligations that determine its funded status as of the end of the employer's fiscal year (with limited exceptions); and (3) recognize changes in the funded status of a plan in the year in which the changes occur through comprehensive income. The funded status of a plan is measured as the difference between plan assets at fair value and the benefit obligation. For a pension plan, the benefit obligation is the projected benefit obligation and for any other postretirement plan it is the accumulated postretirement benefit obligation. Marathon adopted SFAS No. 158 prospectively as of December 31, 2006 and has recognized the funded status of its plans in the consolidated balance sheet as of that date. The adoption of SFAS No. 158 had no impact on Marathon's measurement date as the Company has historically measured the plan assets and benefit obligations of its pension and other postretirement plans as of December 31. See Note 24 for additional disclosures regarding pensions and other postretirement plans required by SFAS No. 158.

        F-12


                The following table illustrates the incremental effect of applying SFAS No. 158 on individual line items of the balance sheet as of December 31, 2006.

        (In millions)

         Before Application of SFAS No. 158
         Adjustments
         After Application of SFAS No. 158
         

         
        Prepaid pensions $229 $(229)$–   
        Investments and long-term receivables  1,893  (6) 1,887 
         Total assets  31,066  (235) 30,831 
        Payroll and benefits payable  384  25  409 
        Defined benefit postretirement plan obligations  870  375  1,245 
        Long-term deferred income taxes  2,183  (286) 1,897 
        Deferred credits and other liabilities  397  (6) 391 
         Total liabilities  15,598  108  15,706 
        Accumulated other comprehensive loss  (25) (343) (368)
         Total stockholders' equity $14,950 $(343)$14,607 

         

        SAB No. 108  –  In September 2006, the Securities and Exchange Commission issued Staff Accounting Bulletin ("SAB") No. 108, "Financial Statements – Considering the Effects of Prior Year Misstatements When Quantifying Misstatements in Current Year Financial Statements." SAB No. 108 addresses how a registrant should quantify the effect of an error in the financial statements for purposes of assessing materiality and requires that the effect be computed using both the current year income statement perspective ("rollover") and the year end balance sheet perspective ("iron curtain") methods for fiscal years ending after November 15, 2006. If a change in the method of quantifying errors is required under SAB No. 108, this represents a change in accounting policy; therefore, if the use of both methods results in a larger, material misstatement than the previously applied method, the financial statements must be adjusted. SAB No. 108 allows the cumulative effect of such adjustments to be made to opening retained earnings upon adoption. Marathon adopted SAB No. 108 for the year ended December 31, 2006, and adoption did not have an effect on Marathon's consolidated results of operations, financial position or cash flows.

        EITF Issue No. 06-03  –  In June 2006, the FASB ratified the consensus reached by the EITF regarding Issue No. 06-03, "How Taxes Collected from Customers and Remitted to Governmental Authorities Should be Presented in the Income Statement (That Is, Gross versus Net Presentation)." Included in the scope of this issue are any taxes assessed by a governmental authority that are imposed on and concurrent with a specific revenue-producing transaction between a seller and a customer. The EITF concluded that the presentation of such taxes on a gross basis (included in revenues and costs) or a net basis (excluded from revenues) is an accounting policy decision that should be disclosed pursuant to Accounting Principles Board ("APB") Opinion No. 22, "Disclosure of Accounting Policies." In addition, the amounts of such taxes reported on a gross basis must be disclosed if those tax amounts are significant. The policy disclosures required by this consensus are included in Note 1 under the heading "Consumer excise taxes" and the taxes reported on a gross basis are presented separately as consumer excise taxes in the consolidated statements of income.

        classification of proved reserves cannot yet be made, FSP No. FAS 19-1 allows exploratory well costs to continue to be capitalized when (1) the well has found a sufficient quantity of reserves to justify completion as a producing well and (2) the enterprise is making sufficient progress assessing the reserves and the economic and operating viability of the project. Marathon’s accounting policy for suspended exploratory well costs was in accordance with FSP No. FAS 19-1 prior to its adoption. FSP No. FAS 19-1 also requires certain disclosures to be made regarding capitalized exploratory well costs which are included in Note 14.
             Effective December 21, 2004, Marathon adopted FSP No. FAS 109-1, “Application of FASB Statement No. 109,Accounting for Income Taxes, to the Tax Deduction on Qualified Production Activities Provided by the American Jobs Creation Act of 2004.” FSP No. FAS 109-1 states the deduction, signed into law on October 22, 2004, of up to 9 percent (when fully phased-in) of the lesser of (1) “qualified production activities income,” as defined in the Act, or (2) taxable income (after the deduction for the utilization of any net operating loss carryforwards) should be accounted for as a special deduction in accordance with SFAS No. 109. Accordingly, Marathon treats qualified production activities income as a special deduction in the years taken.
             Effective July 1, 2004, Marathon adopted FSP No. FAS 106-2, “Accounting and Disclosure Requirements Related to the Medicare Prescription Drug, Improvement and Modernization Act of 2003.” FSP No. FAS 106-2 includes guidance on recognizing the effects of the new legislation under the various conditions surrounding the assessment of “actuarial equivalence.” Marathon has determined, based on available regulatory guidance, that the postretirement plans’ prescription drug benefits are actuarially equivalent to the Medicare “Part D” benefit under the Act. The subsidy-related reduction at July 1, 2004 in the accumulated postretirement benefit obligation for the Marathon postretirement plans was $93 million. The combined favorable pretax effect of the subsidy-related reduction for 2004 on the measurement of the net periodic postretirement benefit cost related to service cost, interest cost and actuarial gain amortization was $7 million.
             Effective July 1, 2004, Marathon adopted FSP No. FAS 142-2, “Application of FASB Statement No. 142,Goodwill and Other Intangible Assets, to Oil- and Gas-Producing Entities.” FSP No. FAS 142-2 states drilling and mineral rights of oil- and gas-producing entities are excluded from SFAS No. 142, “Goodwill and Other Intangible Assets,” and accordingly, should not be classified as intangible assets rather than oil and gas properties. The adoption of FSP No. FAS 142-2 did not have an effect on Marathon’s consolidated financial position, cash flows or results of operations.
             Effective January 1, 2003, Marathon adopted the provisions of SFAS No. 145, “Rescission of FASB Statements No. 4, 44, and 64, Amendment of FASB Statement No. 13, and Technical Corrections,” relating to the classification of the effects of early extinguishment of debt in the consolidated statement of income. As a result, losses from the early extinguishment of debt, which were previously reported as an extraordinary item, will be included in income from continuing operations before income taxes.
             Effective January 1, 2003, Marathon adopted the fair value recognition provisions of SFAS No. 123, “Accounting for Stock-Based Compensation.” SFAS No. 148, “Accounting for Stock-Based Compensation – Transition and Disclosure,” an amendment of SFAS No. 123, provides alternative methods for the transition of accounting for stock-based compensation from the intrinsic value method to the fair value method. Marathon has applied the fair value method to grants made, modified or settled on or after January 1, 2003.
             Effective January 1, 2003, Marathon adopted SFAS No. 143, “Accounting for Asset Retirement Obligations.” The transition adjustment related to adopting SFAS No. 143, was recognized as a cumulative effect of a change in accounting principle. The cumulative effect on net income of adopting SFAS No. 143 was a net favorable effect of $4 million, net of tax of $4 million. At the time of adoption, total assets increased $120 million, and total liabilities increased $116 million.

        EITF Issue No. 04-13  –  In September 2005, the FASB ratified the consensus reached by the EITF on Issue No. 04-13, "Accounting for Purchases and Sales of Inventory with the Same Counterparty." The consensus establishes the circumstances under which two or more inventory purchase and sale transactions with the same counterparty should be recognized at fair value or viewed as a single exchange transaction subject to APB Opinion No. 29, "Accounting for Nonmonetary Transactions." In general, two or more transactions with the same counterparty must be combined for purposes of applying APB Opinion No. 29 if they are entered into in contemplation of each other. The purchase and sale transactions may be pursuant to a single contractual arrangement or separate contractual arrangements and the inventory purchased or sold may be in the form of raw materials, work-in-process or finished goods.

                Effective April 1, 2006, Marathon adopted the provisions of EITF Issue No. 04-13 prospectively. EITF Issue No. 04-13 changes the accounting for matching buy/sell arrangements that are entered into or modified on or after April 1, 2006 (except for those accounted for as derivative instruments, which are discussed below). In a typical matching buy/sell transaction, Marathon enters into a contract to sell a particular quantity and quality of crude oil or refined product at a specified location and date to a particular counterparty and simultaneously agrees to buy a particular quantity and quality of the same commodity at a specified location on the same or another specified date from the same counterparty. Prior to adoption of EITF Issue No. 04-13, Marathon recorded such matching buy/sell transactions in both revenues and cost of revenues as separate sale and purchase transactions. Upon adoption, these transactions are accounted for as exchanges of inventory.

                The scope of EITF Issue No. 04-13 excludes matching buy/sell arrangements that are accounted for as derivative instruments. A portion of Marathon's matching buy/sell transactions are "nontraditional derivative instruments," which are discussed in Note 1. Although the accounting for nontraditional derivative instruments is outside the scope of EITF Issue No. 04-13, the conclusions reached in that consensus caused Marathon to reconsider the guidance in EITF Issue No. 03-11, "Reporting Realized Gains and Losses on Derivative Instruments That Are Subject to FASB Statement No. 133 and Not "Held for Trading Purposes" as Defined in Issue No. 02-3." As a result, effective for contracts entered into or modified on or after April 1, 2006, the effects of matching buy/sell arrangements accounted for as nontraditional derivative instruments are recognized on a net basis in net income and are classified as cost of revenues. Prior to this change, Marathon recorded these transactions in both revenues and cost of revenues as separate sale and purchase transactions. This change in accounting principle is being applied on a prospective basis because it is impracticable to apply the change on a retrospective basis.

        F-13


                Transactions arising from all matching buy/sell arrangements entered into before April 1, 2006 will continue to be reported as separate sale and purchase transactions.

                The adoption of EITF Issue No. 04-13 and the change in the accounting for nontraditional derivative instruments had no effect on net income. The amounts of revenues and cost of revenues recognized after April 1, 2006 are less than the amounts that would have been recognized under previous accounting practices.

        SFAS No. 123 (Revised 2004)  –  In December 2004, the FASB issued SFAS No. 123(R), "Share-Based Payment," as a revision of SFAS No. 123, "Accounting for Stock-Based Compensation." This statement requires entities to measure the cost of employee services received in exchange for an award of equity instruments based on the fair value of the award on the grant date. That cost is recognized over the period during which an employee is required to provide service in exchange for the award, usually the vesting period. In addition, awards classified as liabilities are remeasured at fair value each reporting period. Marathon had previously adopted the fair value method under SFAS No. 123 for grants made, modified or settled on or after January 1, 2003.

                SFAS No. 123(R) also requires a company to calculate the pool of excess tax benefits available to absorb tax deficiencies recognized subsequent to adopting the statement. In November 2005, the FASB issued FSP No. 123R-3, "Transition Election Related to Accounting for the Tax Effects of Share-Based Payment Awards," to provide an alternative transition election (the "short-cut method") to account for the tax effects of share-based payment awards to employees. Marathon elected the long-form method to determine its pool of excess tax benefits as of January 1, 2006.

                Marathon adopted SFAS No. 123(R) as of January 1, 2006, for all awards granted, modified or cancelled after adoption and for the unvested portion of awards outstanding at January 1, 2006. At the date of adoption, SFAS No. 123(R) requires that an assumed forfeiture rate be applied to any unvested awards and that awards classified as liabilities be measured at fair value. Prior to adopting SFAS No. 123(R), Marathon recognized forfeitures as they occurred and applied the intrinsic value method to awards classified as liabilities. The adoption did not have a significant effect on Marathon's consolidated results of operations, financial position or cash flows.

        SFAS No. 151  –  Effective January 1, 2006, Marathon adopted SFAS No. 151, "Inventory Costs – an amendment of ARB No. 43, Chapter 4." This statement requires that items such as idle facility expense, excessive spoilage, double freight and re-handling costs be recognized as a current-period charge. The adoption did not have a significant effect on Marathon's consolidated results of operations, financial position or cash flows.

        SFAS No. 154  –  Effective January 1, 2006, Marathon adopted SFAS No. 154, "Accounting Changes and Error Corrections – A Replacement of APB Opinion No. 20 and FASB Statement No. 3." SFAS No. 154 requires companies to recognize (1) voluntary changes in accounting principle and (2) changes required by a new accounting pronouncement, when the pronouncement does not include specific transition provisions, retrospectively to prior periods' financial statements, unless it is impracticable to determine either the period-specific effects or the cumulative effect of the change.

        FIN No. 47  –  In March 2005, the FASB issued FASB Interpretation ("FIN") No. 47, "Accounting for Conditional Asset Retirement Obligations – an interpretation of FASB Statement No. 143." This interpretation clarifies that an entity is required to recognize a liability for a legal obligation to perform asset retirement activities when the retirement is conditional on a future event if the liability's fair value can be reasonably estimated. If the liability's fair value cannot be reasonably estimated, then the entity must disclose (1) a description of the obligation, (2) the fact that a liability has not been recognized because the fair value cannot be reasonably estimated and (3) the reasons why the fair value cannot be reasonably estimated. FIN No. 47 also clarifies when an entity would have sufficient information to reasonably estimate the fair value of an asset retirement obligation. Marathon adopted FIN No. 47 as of December 31, 2005. A charge of $19 million, net of taxes of $12 million, related to adopting FIN No. 47 was recognized as a cumulative effect of a change in accounting principle in 2005. At the time of adoption, total assets increased $22 million and total liabilities increased $41 million.

                The pro forma net income and net income per share effect as if FIN No. 47 had been applied during 2005 and 2004 is not significantly different than amounts reported. The following summarizes the total amount of the liability for asset retirement obligations as if FIN No. 47 had been applied during all periods presented. The pro forma impact of the adoption of FIN No. 47 on these unaudited pro forma liability amounts has been measured using the information, assumptions and interest rates used to measure the obligation recognized upon adoption of FIN No. 47.

        (In millions)

          

        December 31, 2003 $438
        December 31, 2004  527
        December 31, 2005  711

        SFAS No. 153  –  Marathon adopted SFAS No. 153, "Exchanges of Nonmonetary Assets – an amendment of APB Opinion No. 29," on a prospective basis as of July 1, 2005. This amendment eliminates the APB Opinion No. 29 exception for fair value recognition of nonmonetary exchanges of similar productive assets and replaces it with an exception for exchanges of nonmonetary assets that do not have commercial substance.

        FSP No. FAS 19-1  –  Effective January 1, 2005, Marathon adopted FSP No. FAS 19-1, "Accounting for Suspended Well Costs," which amended the guidance for suspended exploratory well costs in SFAS No. 19, "Financial Accounting and Reporting by Oil and Gas Producing Companies." SFAS No. 19 requires costs of drilling exploratory wells to be capitalized pending determination of whether the well has found proved reserves. When a classification of proved

        F-14



        reserves cannot yet be made, FSP No. FAS 19-1 allows exploratory well costs to continue to be capitalized when (1) the well has found a sufficient quantity of reserves to justify completion as a producing well and (2) the enterprise is making sufficient progress assessing the reserves and the economic and operating viability of the project. Marathon's accounting policy for suspended exploratory well costs was in accordance with FSP No. FAS 19-1 prior to its adoption. FSP No. FAS 19-1 also requires certain disclosures to be made regarding capitalized exploratory well costs which are included in Note 15.

        FSP No. FAS 109-1  –  Effective December 21, 2004, Marathon adopted FSP No. FAS 109-1, "Application of FASB Statement No. 109,Accounting for Income Taxes, to the Tax Deduction on Qualified Production Activities Provided by the American Jobs Creation Act of 2004." FSP No. FAS 109-1 states the deduction, signed into law on October 22, 2004, of up to 9 percent (when fully phased-in) of the lesser of (1) "qualified production activities income," as defined in the Act, or (2) taxable income (after the deduction for the utilization of any net operating loss carryforwards) should be accounted for as a special deduction in accordance with SFAS No. 109. Accordingly, Marathon treats the deduction related to production activities income as a special deduction in the years taken.

        FSP No. FAS 106-2  –  Effective July 1, 2004, Marathon adopted FSP No. FAS 106-2, "Accounting and Disclosure Requirements Related to the Medicare Prescription Drug, Improvement and Modernization Act of 2003." FSP No. FAS 106-2 includes guidance on recognizing the effects of the new legislation under the various conditions surrounding the assessment of "actuarial equivalence." Marathon has determined, based on available regulatory guidance, that the postretirement plans' prescription drug benefits are actuarially equivalent to the Medicare "Part D" benefit under the Act. The subsidy-related reduction at July 1, 2004 in the accumulated postretirement benefit obligation for the Marathon postretirement benefit plans was $93 million. The combined favorable pretax effect of the subsidy-related reduction for 2004 on the measurement of the net periodic postretirement benefit cost related to service cost, interest cost and actuarial gain amortization was $7 million.


        3. Information about United States Steel

        The Separation – Prior to December 31, 2001, Marathon had two outstanding classes of common stock: USX – Marathon Group common stock, which was intended to reflect the performance of Marathon’s energy business, and USX – U.S. Steel Group common stock (“Steel Stock”), which was intended to reflect the performance of Marathon’s steel business. On December 31, 2001, in a tax-free distribution to holders of Steel Stock, Marathon exchanged the common stock of United States Steel for all outstanding shares of Steel Stock on a one-for-one basis (“the Separation”).
             In connection with the Separation, Marathon and United States Steel entered into a number of agreements, including:
        Financial Matters Agreement – Marathon and United States Steel have entered into a Financial Matters Agreement that provides for United States Steel’s assumption of certain industrial revenue bonds and certain other financial obligations of Marathon. The Financial Matters Agreement also provides that, on or before the tenth anniversary of the Separation, United States Steel will provide for Marathon’s discharge from any remaining liability under any of the assumed industrial revenue bonds.
             Under the Financial Matters Agreement, United States Steel has all of the existing contractual rights under the leases assumed from Marathon, including all rights related to purchase options, prepayments or the grant or

        F-15The Separation  –  Prior to December 31, 2001, Marathon had two outstanding classes of common stock: USX – Marathon Group common stock, which was intended to reflect the performance of Marathon's energy business, and USX – U.S. Steel Group common stock ("Steel Stock"), which was intended to reflect the performance of Marathon's steel business. On December 31, 2001, in a tax-free distribution to holders of Steel Stock, Marathon exchanged the common stock of United States Steel for all outstanding shares of Steel Stock on a one-for-one basis (the "Separation"). In connection with the Separation, Marathon and United States Steel entered into a number of agreements, including:

        Financial Matters Agreement  –  Marathon and United States Steel have entered into a Financial Matters Agreement that provides for United States Steel's assumption of certain industrial revenue bonds and certain other financial obligations of Marathon. The Financial Matters Agreement also provides that, on or before the tenth anniversary of the Separation, United States Steel will provide for Marathon's discharge from any remaining liability under any of the assumed industrial revenue bonds.

                Under the Financial Matters Agreement, United States Steel has all of the existing contractual rights under the leases assumed from Marathon, including all rights related to purchase options, prepayments or the grant or release of security interests. However, United States Steel has no right to increase amounts due under or lengthen the term of any of the assumed leases, other than extensions set forth in the terms of any of the assumed leases.

                United States Steel is the sole general partner of Clairton 1314B Partnership, L.P., which owns certain cokemaking facilities formerly owned by United States Steel. Marathon has guaranteed to the limited partners all obligations of United States Steel under the partnership documents. The Financial Matters Agreement requires United States Steel to use commercially reasonable efforts to have Marathon released from its obligations under this guarantee. United States Steel may dissolve the partnership under certain circumstances, including if it is required to fund accumulated cash shortfalls of the partnership in excess of $150 million. In addition to the normal commitments of a general partner, United States Steel has indemnified the limited partners for certain income tax exposures.

                The Financial Matters Agreement requires Marathon to use commercially reasonable efforts to assure compliance with all covenants and other obligations to avoid the occurrence of a default or the acceleration of payments on the assumed obligations.

                United States Steel's obligations to Marathon under the Financial Matters Agreement are general unsecured obligations that rank equal to United States Steel's accounts payable and other general unsecured obligations. The Financial Matters Agreement does not contain any financial covenants and United States Steel is free to incur additional debt, grant mortgages on or security interests in its property and sell or transfer assets without Marathon's consent.

        Tax Sharing Agreement  –  Marathon and United States Steel have entered into a Tax Sharing Agreement that reflects each party's rights and obligations relating to payments and refunds of income, sales, transfer and other taxes that are attributable to periods beginning prior to and including the Separation date and taxes resulting from transactions effected in connection with the Separation.

                In 2006 and 2005, in accordance with the terms of the Tax Sharing Agreement, Marathon paid $35 million and $6 million to United States Steel in connection with the settlement with the Internal Revenue Service of the consolidated federal income tax returns of USX Corporation for the years 1995 through 2001. The final payment of $13 million to United States Steel related to U.S. federal tax returns under the Tax Sharing Agreement was made in January 2007.

        F-15


        release of security interests. However, United States Steel has no right to increase amounts due under or lengthen the term of any of the assumed leases, other than extensions set forth in the terms of any of the assumed leases.
             United States Steel is the sole general partner of Clairton 1314B Partnership, L.P., which owns certain cokemaking facilities formerly owned by United States Steel. Marathon has guaranteed to the limited partners all obligations of United States Steel under the partnership documents. The Financial Matters Agreement requires United States Steel to use commercially reasonable efforts to have Marathon released from its obligations under this guarantee. United States Steel may dissolve the partnership under certain circumstances, including if it is required to fund accumulated cash shortfalls of the partnership in excess of $150 million. In addition to the normal commitments of a general partner, United States Steel has indemnified the limited partners for certain income tax exposures.
             The Financial Matters Agreement requires Marathon to use commercially reasonable efforts to assure compliance with all covenants and other obligations to avoid the occurrence of a default or the acceleration of payments on the assumed obligations.
             United States Steel’s obligations to Marathon under the Financial Matters Agreement are general unsecured obligations that rank equal to United States Steel’s accounts payable and other general unsecured obligations. The Financial Matters Agreement does not contain any financial covenants and United States Steel is free to incur additional debt, grant mortgages on or security interests in its property and sell or transfer assets without Marathon’s consent.

        Tax Sharing Agreement – Marathon and United States Steel have entered into a Tax Sharing Agreement that reflects each party’s rights and obligations relating to payments and refunds of income, sales, transfer and other taxes that are attributable to periods beginning prior to and including the Separation Date and taxes resulting from transactions effected in connection with the Separation.
             The Tax Sharing Agreement incorporates the general tax sharing principles of the former tax allocation policy. In general, Marathon and United States Steel will make payments between them such that, with respect to any consolidated, combined or unitary tax returns for any taxable period or portion thereof ending on or before the Separation Date, the amount of taxes to be paid by each of Marathon and United States Steel will be determined, subject to certain adjustments, as if the former groups each filed their own consolidated, combined or unitary tax return. The Tax Sharing Agreement also provides for payments between Marathon and United States Steel for certain tax adjustments that may be made after the Separation. Other provisions address, but are not limited to, the handling of tax audits, settlements and return filing in cases where both Marathon and United States Steel have an interest in the results of these activities.
             In 2005, 2004 and 2003, in accordance with the terms of the tax sharing agreement, Marathon paid $6 million, $3 million and $16 million to United States Steel in connection with the settlement with the Internal Revenue Service of the consolidated federal income tax returns of USX Corporation for the years 1992 through 1997. Included in discontinued operations in 2003 is an $8 million adjustment to the liabilities to United States Steel under this tax sharing agreement.
        Relationship between Marathon and United States Steel after the Separation – As a result of the Separation, Marathon and United States Steel are separate companies and neither has any ownership interest in the other. As of December 31, 2005, Thomas J. Usher was the non-executive chairman of the board of both companies and four of the ten remaining members of Marathon’s board of directors are also directors of United States Steel. Mr. Usher retired as chairman of United States Steel on January 31, 2006. At that date, he and one other Marathon board member left United States Steel’s board of directors.
             Sales to United States Steel in 2005, 2004 and 2003 were $31 million, $30 million and $31 million, primarily for natural gas. Purchases from United States Steel in 2005, 2004 and 2003 were $39 million, $27 million and $14 million, primarily for raw materials. Management believes that transactions with United States Steel were conducted under terms comparable to those with unrelated parties. Marathon reimbursed United States Steel $1 million and $3 million, respectively, in 2005 and 2004, for the payment of benefits to retirees, including Mr. Usher, under United States Steel’s 2001 plan of reorganization.
        Amounts receivable from or payable to United States Steel arising from the Separation – As previously discussed, Marathon remains primarily obligated for certain financings for which United States Steel has assumed responsibility for repayment under the terms of the Separation. When United States Steel makes payments on the principal of these financings, both the receivable from United States Steel and the obligation are reduced.

        F-16Amounts receivable from or payable to United States Steel arising from the Separation  –  As previously discussed, Marathon remains primarily obligated for certain financings for which United States Steel has assumed responsibility for repayment under the terms of the Separation. When United States Steel makes payments on the principal of these financings, both the receivable from United States Steel and the obligation are reduced.


                At December 31, 2006 and 2005, amounts receivable from or payable to United States Steel included in the consolidated balance sheets were as follows:

        (In millions)                                                                                                                                 December 31
         2006
         2005

        Receivables related to debt and other obligations for which United States Steel
        has assumed responsibility for repayment:
              
         Current $32 $20
         Noncurrent  498  532
        Current payable for interest related to tax settlements  13  –  
        Noncurrent reimbursements payable under nonqualified defined benefit postretirement plans  7  6

                Marathon remains primarily obligated for $34 million of operating lease obligations assumed by United States Steel, of which $31 million has been assumed by third parties that purchased plants and operations divested by United States Steel.

                In addition, Marathon remains contingently liable for certain obligations of United States Steel. See Note 30 for further information regarding these guarantees.

             At December 31, 2005 and 2004, amounts receivable from or payable to United States Steel included in the consolidated balance sheets were as follows:

                  
        (In millions)December 312005 2004
         
        Receivables related to debt and other obligations for which United States Steel has assumed responsibility for repayment:        
         Current $20  $15 
               
         Noncurrent  532   587 
               
        Noncurrent reimbursements payable under nonqualified employee benefit plans $6  $5 
         
             Marathon remains primarily obligated for $45 million of operating lease obligations assumed by United States Steel, of which $37 million has been assumed by third parties that purchased plants and operations divested by United States Steel.
             In addition, Marathon remains contingently liable for certain obligations of United States Steel. See Note 28 for additional details on these guarantees.

        4. Variable Interest Entities

        Equatorial Guinea LNG Holdings Limited ("EGHoldings"), in which Marathon holds a 60 percent interest and which was formed for the purpose of constructing and operating an LNG production facility, is a VIE that is consolidated. As of December 31, 2006, total expenditures of $1.363 billion related to the LNG production facility, including $1.300 billion of capital expenditures, have been incurred. The Andersons Marathon Ethanol LLC, a joint venture in which Marathon and its partner each hold a 50 percent interest and which was formed in 2006 for the purpose of constructing and operating one or more ethanol production plants, is a VIE that is not consolidated. As of December 31, 2006, Marathon had contributed $11 million to The Andersons Marathon Ethanol LLC.


        5. Related Party Transactions

        Related parties include:
        Ashland Inc. (“Ashland”), which held a 38 percent ownership interest in MPC, a consolidated subsidiary, until June 30, 2005;
        Compania Nacional de Petroleos de Guinea Ecuatorial (“GEPetrol”), Mitsui & Co., Ltd. (“Mitsui”) and Marubeni Corporation (“Marubeni”), which hold ownership interests in EGHoldings, a consolidated subsidiary; and
        Equity method investees. See “Principal Unconsolidated Investees” on page F-42 for major investees.
        Management believes that transactions with related parties were conducted under terms comparable to those with unrelated parties.
             Related party sales to Ashland and Pilot Travel Centers LLC (“PTC”) consist primarily of petroleum products. Revenues from related parties were as follows:
                       
        (In millions) 2005 2004 2003
         
        Ashland $132  $274  $258 
        Equity method investees:            
         PTC  1,205   715   635 
         Centennial Pipeline LLC (“Centennial”)  47   49   16 
         Other  18   13   12 
                  
          Total $1,402  $1,051  $921 
         
             Purchases from related parties were as follows:
                       
        (In millions) 2005 2004 2003
         
        Ashland $12  $22  $24 
        Equity method investees:            
         Centennial  73   56   49 
         Other  140   124   136 
                  
          Total $225  $202  $209 
         
             Receivables from related parties were as follows:
                   
        (In millions) December 312005 2004
         
        Ashland $–   $18 
        Equity method investees:        
         PTC  34   19 
         Alba Plant LLC  3   17 
         Centennial  –    16 
         Other  1   4 
               
          Total $38  $74 
         

        F-17Related parties during 2006, 2005 and 2004 include:

        Sociedad Nacional de Gas de Guinea Ecuatorial ("SONAGAS"), which has held a 25 percent ownership interest in EGHoldings, a consolidated subsidiary, since November 14, 2006;
        Mitsui & Co., Ltd. ("Mitsui") and Marubeni Corporation ("Marubeni"), which have held 8.5 percent and 6.5 percent ownership interests in EGHoldings since July 25, 2005;
        Compania Nacional de Petroleos de Guinea Ecuatorial ("GEPetrol"), which held a 25 percent ownership interest in EGHoldings until November 14, 2006;
        Ashland Inc. ("Ashland"), which held a 38 percent ownership interest in MPC, a consolidated subsidiary, until June 30, 2005; and
        Equity method investees. See "Principal Unconsolidated Investees" on page F-42 for major investees.

        Management believes that transactions with related parties were conducted under terms comparable to those with unrelated parties.

                Related party sales to Pilot Travel Centers LLC ("PTC") and Ashland consist primarily of petroleum products. Revenues from related parties were as follows:

        (In millions)

         2006
         2005
         2004

        Equity method investees:         
         PTC $1,420 $1,205 $715
         Centennial Pipeline LLC ("Centennial")  28  47  49
         Other equity method investees  18  18  13
        Ashland  –    132  274
          
         
         
          Total $1,466 $1,402 $1,051

                Purchases from related parties were as follows:

        (In millions)

         2006
         2005
         2004

        Equity method investees:         
         LOOP LLC $54 $49 $44
         Centennial  53  73  56
         Other equity method investees  103  91  80
        Ashland  –    12  22
          
         
         
          Total $210 $225 $202

        F-16


                Current receivables from related parties were as follows:

        (In millions)

         December 31
         2006
         2005

        Equity method investees:        
         PTC   $41 $34
         Other equity method investees    9  4
        Other related parties    13  –  
            
         
          Total   $63 $38

                Payables to related parties were as follows:

        (In millions)

         December 31
         2006
         2005

        SONAGAS   $229 $–  
        GEPetrol    –    57
        Equity method investees:        
         Alba Plant LLC    15  14
         Other equity method investees    17  11
        Other related parties    3  –  
            
         
          Total   $264 $82

                MPC had a $190 million uncommitted revolving credit agreement with Ashland that terminated in March 2005. Interest paid to Ashland for borrowings under this agreement was less than $1 million in each of 2005 and 2004.

                Cash of $234 million held in escrow for future capital contributions from SONAGAS to EGHoldings is classified as restricted cash and is included in investments and long-term receivables as of December 31, 2006.


        6. Acquisitions

        Minority interest in MPC  –  On June 30, 2005, Marathon acquired the 38 percent ownership interest in Marathon Ashland Petroleum LLC ("MAP") previously held by Ashland. In addition, Marathon acquired a portion of Ashland's Valvoline Instant Oil Change business, its maleic anhydride business, its interest in LOOP LLC, which owns and operates the only U.S. deepwater oil port, and its interest in LOCAP LLC, which owns a crude oil pipeline. As a result of the transactions (the "Acquisition"), MAP is now wholly owned by Marathon and its name was changed to Marathon Petroleum Company LLC ("MPC") effective September 1, 2005. The Acquisition was accounted for under the purchase method of accounting and, as such, Marathon's results of operations include the results of the acquired businesses from June 30, 2005. The total consideration, including debt assumed, is as follows:

        (In millions)

          

        Cash(a) $487
        MPC accounts receivable(a)  911
        Marathon common stock(b)  955
        Estimated additional consideration related to tax matters  75
        Transaction-related costs  10
          
         Purchase price  2,438
        Assumption of debt(c)  1,920
          
         Total consideration including debt assumption(d) $4,358

        (a)
        The MAP Limited Liability Company Agreement was amended to eliminate the requirement for MPC to make quarterly cash distributions to Marathon and Ashland between the date the principal transaction agreements were signed and the closing of the Acquisition. Cash and MPC accounts receivable above include $506 million representing Ashland's 38 percent of MPC's distributable cash as of June 30, 2005.
        (a)
        Ashland shareholders received 17.539 million shares valued at $54.45 per share, which was Marathon's average common stock price over the trading days between June 23 and June 29, 2005. The exchange ratio was designed to provide an aggregate number of Marathon shares worth $915 million based on Marathon's average common stock price for each of the 20 consecutive trading days ending with the third complete trading day prior to June 30, 2005.
        (a)
        Assumed debt was repaid on July 1, 2005.
        (a)
        Marathon is entitled to certain tax deductions related to businesses previously owned by Ashland. However, pursuant to the terms of the tax matters agreement, Marathon has agreed to reimburse Ashland for a portion of the tax benefits associated with these deductions. This additional consideration will be included in the purchase price as amounts owed to Ashland are identified. During 2006, an additional $17 million was included in the purchase price for such amounts.

        F-17


                The primary reasons for the Acquisition and the principal factors that contributed to a purchase price that resulted in the recognition of goodwill were:

        Marathon believed the outlook for the refining and marketing business was attractive in MPC's core areas of operation. Complete ownership of MPC provided Marathon the opportunity to leverage MPC's access to premium U.S. markets where Marathon expected the levels of demand to remain high for the foreseeable future;
        The Acquisition increased Marathon's participation in the RM&T business without the risks commonly associated with integrating a newly acquired business;
        MPC provided Marathon with an increased source of cash flow which Marathon believed enhanced the geographical balance in its overall risk portfolio;
        Marathon anticipated the transaction would be accretive to income per share;
        The Acquisition eliminated the timing and valuation uncertainties associated with the exercise of the Put/Call, Registration Rights and Standstill Agreement entered into with the formation of MPC in 1998, as well as the associated premium and discount; and
        The Acquisition eliminated the possibility that a misalignment of Ashland's and Marathon's interests, as co-owners of MPC, could adversely affect MPC's future growth and financial performance.

                The following table summarizes the estimated fair values of the assets acquired and liabilities assumed as of June 30, 2005.

        (In millions)

          

        Current assets:   
         Cash and cash equivalents $518
         Receivables  1,080
         Inventories  1,866
         Other current assets  28
          
          Total current assets acquired  3,492
         Investments and long-term receivables  484
         Property, plant and equipment  2,671
         Goodwill  853
         Intangible assets  112
         Other noncurrent assets  8
          
          Total assets acquired $7,620
          
        Current liabilities:   
         Notes payable $1,920
         Deferred income taxes  669
         Other current liabilities  1,686
          
          Total current liabilities assumed  4,275
        Long-term debt  16
        Deferred income taxes  374
        Defined benefit postretirement plan obligations  470
        Other liabilities  47
          
          Total liabilities assumed $5,182
          
           Net assets acquired $2,438

                The goodwill arising from the purchase price allocation was $853 million, which was assigned to the RM&T segment. None of the goodwill is deductible for tax purposes. Of the $112 million allocated to intangible assets, $49 million was allocated to retail marketing tradenames with indefinite lives.

                The purchase price allocated to equity method investments is $230 million higher than the underlying net assets of the investees. This excess will be amortized over the expected useful lives of the underlying assets except for $144 million of the excess related to goodwill.

        Libya re-entry  –  On December 29, 2005, Marathon, in conjunction with its partners in the former Oasis Group, entered into an agreement with the National Oil Corporation of Libya to return to its oil and natural gas exploration and production operations in the Waha concessions in Libya. Marathon holds a 16.33 percent interest in the Waha concessions and was required to cease operations there in 1986 to comply with U.S. government sanctions. Over time, Marathon had written off all its assets in Libya. The re-entry terms include a 25-year extension of the concessions to 2030 through 2034 and payments from Marathon of $520 million and $198 million, which were made in January and December 2006.

                The primary reasons for the transaction and the principal factors that contributed to a purchase price that resulted in the recognition of goodwill include the fact that the re-entry allows Marathon to expand its exploration and production operations without many of the risks commonly associated with integrating a newly acquired business including having a trained workforce in place that has maintained operations and added to the hydrocarbon resource during the absence of Marathon and its partners. The transaction also could assist Marathon in identifying and participating in potential future projects in Libya.

        F-18


             Payables to related parties were as follows:

                   
        (In millions)December 312005 2004
         
        GEPetrol $57  $23 
        Equity method investees:        
         Alba Plant LLC  14   –  
         Centennial  1   12 
         Other  10   9 
               
          Total $82  $44 
         
             MPC had a $190 million uncommitted revolving credit agreement with Ashland that terminated in March 2005. Interest paid to Ashland for borrowings under this agreement was less than $1 million in each of 2005, 2004 and 2003.
             Cash of $57 million held in escrow for future contributions to EGHoldings from GEPetrol is classified as restricted cash and is included in investments and long-term receivables as of December 31, 2005.
        5.  Acquisitions
        Minority Interest in MPC
        On June 30, 2005, Marathon acquired the 38 percent ownership interest in Marathon Ashland Petroleum LLC (“MAP”) previously held by Ashland. In addition, Marathon acquired a portion of Ashland’s Valvoline Instant Oil Change business, its maleic anhydride business, its interest in LOOP LLC, which owns and operates the only U.S. deepwater oil port, and its interest in LOCAP LLC, which owns a crude oil pipeline. As a result of the transactions (the “Acquisition”), MAP is now wholly owned by Marathon and its name was changed to Marathon Petroleum Company LLC (“MPC”) effective September 1, 2005. The Acquisition was accounted for under the purchase method of accounting and, as such, Marathon’s results of operations include the results of the acquired businesses from June 30, 2005. The total consideration, including debt assumed, is as follows:
              
        (In millions)  
         
        Cash(a)
         $487 
        MPC accounts receivable(a)
          911 
        Marathon common stock(b)
          955 
        Estimated additional consideration related to tax matters  58 
        Transaction-related costs  10 
            
         Purchase price  2,421 
        Assumption of debt(c)
          1,920 
            
         
        Total consideration including debt assumption(d)
         $4,341 
         
        (a)The MAP Limited Liability Company Agreement was amended to eliminate the requirement for MPC to make quarterly cash distributions to Marathon and Ashland between the date the principal transaction agreements were signed and the closing of the Acquisition. Cash and MPC accounts receivable above include $506 million representing Ashland’s 38 percent of MPC’s distributable cash as of June 30, 2005.
        (b)Ashland shareholders received 17.539 million shares valued at $54.45 per share, which was Marathon’s average common stock price over the trading days between June 23 and June 29, 2005. The exchange ratio was designed to provide an aggregate number of Marathon shares worth $915 million based on Marathon’s average common stock price for each of the 20 consecutive trading days ending with the third complete trading day prior to June 30, 2005.
        (c)Assumed debt was repaid on July 1, 2005.
        (d)Marathon is entitled to the tax deductions for Ashland’s future payments of certain contingent liabilities related to businesses previously owned by Ashland. However, pursuant to the terms of the Tax Matters Agreement, Marathon has agreed to reimburse Ashland for a portion of these future payments. This contingent consideration will be included in the purchase price as such payments are made to Ashland.

        F-18        The operational re-entry date under the terms of the agreement was January 1, 2006; therefore, Marathon's consolidated results of operations for 2005 do not include any results from the operations of the Waha concessions. The transaction was accounted for under the purchase method of accounting.


                The following table summarizes the estimated fair values of the assets acquired and liabilities assumed as of December 29, 2005.

        (In millions)

          

        Current assets:   
         Inventories $10
         Other current assets  7
          
          Total current assets acquired  17
        Property, plant and equipment  719
        Deferred income tax assets  175
        Goodwill  309
          
          Total assets acquired $1,220
          
        Current liabilities:   
         Accounts payable $17
        Other liabilities  6
        Deferred income tax liabilities  479
          
          Total liabilities assumed $502
          
           Net assets acquired $718

                The goodwill arising from the purchase price allocation was $309 million, which was assigned to the E&P segment. None of the goodwill is deductible for tax purposes.

                The following unaudited pro forma data is as if the Acquisition and the re-entry to the Libya concessions had been consummated at the beginning of each period presented. The pro forma data is based on historical information and does not reflect the actual results that would have occurred nor is it indicative of future results of operations.

        (In millions, except per share amounts)

         2005
         2004

        Revenues and other income $65,614 $50,670
        Income from continuing operations  3,315  1,596
        Net income  3,341  1,563
        Per share data:      
         Income from continuing operations – basic $9.09 $4.51
         Income from continuing operations – diluted $9.01 $4.49
         Net income – basic $9.16 $4.42
         Net income – diluted $9.08 $4.39

             The primary reasons for the Acquisition and the principal factors that contributed to a purchase price that resulted in the recognition of goodwill are:
        Marathon believes the outlook for the refining and marketing business is attractive in MPC’s core areas of operation. Complete ownership of MPC provides Marathon the opportunity to leverage MPC’s access to premium U.S. markets where Marathon expects the levels of demand to remain high for the foreseeable future;
        The Acquisition increases Marathon’s participation in the RM&T business without the risks commonly associated with integrating a newly acquired business;
        MPC provides Marathon with an increased source of cash flow which Marathon believes enhances the geographical balance in its overall risk portfolio;
        Marathon anticipates the transaction will be accretive to income per share;
        The Acquisition eliminated the timing and valuation uncertainties associated with the exercise of the Put/Call, Registration Rights and Standstill Agreement entered into with the formation of MPC in 1998, as well as the associated premium and discount; and
        The Acquisition eliminated the possibility that a misalignment of Ashland’s and Marathon’s interests, as co-owners of MPC, could adversely affect MPC’s future growth and financial performance.
             The following table summarizes the estimated fair values of the assets acquired and liabilities assumed as of June 30, 2005.
                
        (In millions)  
         
        Current assets:    
         Cash and cash equivalents $518 
         Receivables  1,080 
         Inventories  1,866 
         Other current assets  28 
            
          Total current assets acquired  3,492 
         Investments and long-term receivables  484 
         Property, plant and equipment  2,671 
         Goodwill  735 
         Intangibles  112 
         Other noncurrent assets  8 
            
          Total assets acquired $7,502 
            
        Current liabilities:    
         Notes payable $1,920 
         Deferred income taxes  669 
         Other current liabilities  1,694 
            
          Total current liabilities assumed  4,283 
        Long-term debt  16 
        Deferred income taxes  265 
        Employee benefits obligations  484 
        Other liabilities  33 
            
          Total liabilities assumed $5,081 
            
           Net assets acquired $2,421 
         
             The goodwill arising from the purchase price allocation was $735 million, which was assigned to the RM&T segment. None of the goodwill is deductible for tax purposes. Of the $112 million allocated to intangible assets, $49 million was allocated to retail marketing tradenames with indefinite lives.
             The purchase price allocated to equity method investments is $230 million higher than the underlying net assets of the investees. This excess will be amortized over the expected useful life of the underlying assets except for $144 million of the excess related to goodwill.

        Libya Re-entry
        On December 29, 2005, Marathon, in conjunction with its partners in the former Oasis Group, entered into an agreement with the National Oil Corporation of Libya to return to its oil and natural gas exploration and production operations in the Waha concessions in Libya. Marathon holds a 16.33 percent interest in the Waha concessions and was required to cease operations there in 1986 to comply with U.S. government sanctions. Over time, Marathon had written off all its assets in Libya. The re-entry terms include a 25-year extension of the concessions to 2030 through 2034 and a payment of $520 million from Marathon, which was made in January 2006. An additional payment estimated to be approximately $212 million is payable by Marathon within one year of the agreement date.
             The primary reasons for the transaction and the principal factors that contributed to a purchase price that resulted in the recognition of goodwill include the fact that the re-entry allows Marathon to expand its exploration and production operations without many of the risks commonly associated with integrating a newly acquired

        F-19


        business including having a trained workforce in place that has maintained operations and added to the hydrocarbon resource during the absence of Marathon and its partners. The transaction also could assist Marathon in identifying and participating in potential future projects in Libya.
             The operational re-entry date under the terms of the agreement is January 1, 2006; therefore, Marathon’s consolidated results of operations for 2005 do not include any results from the operations of the Waha concessions. The transaction was accounted for under the purchase method of accounting.
             The following table summarizes the estimated fair values of the assets acquired and liabilities assumed as of December 29, 2005. Marathon is in the process of finalizing the fair value estimates for certain assets and liabilities; thus the allocation of the purchase price is preliminary.

                
        (In millions)  
         
        Current assets:    
         Inventories $10 
         Other current assets  8 
            
          Total current assets acquired  18 
        Property, plant and equipment  732 
        Goodwill  315 
            
          Total assets acquired $1,065 
            
        Current liabilities:    
         Accounts payable $10 
        Other liabilities  4 
        Deferred income taxes  319 
            
          Total liabilities assumed $333 
            
           Net assets acquired $732 
         
             The goodwill arising from the preliminary purchase price allocation was $315 million, which was assigned to the E&P segment. None of the goodwill is deductible for tax purposes.
             The following unaudited pro forma data is as if the Acquisition and the re-entry to the Libya concessions had been consummated at the beginning of each period presented. The pro forma data is based on historical information and does not reflect the actual results that would have occurred nor is it indicative of future results of operations.
                  
        (In millions, except per share amounts) 2005 2004
         
        Revenues and other income $64,829  $50,803 
        Income from continuing operations  3,807   1,559 
        Net income  3,290   1,563 
        Per share data:        
         Income from continuing operations – basic $10.44  $4.40 
         Income from continuing operations – diluted $10.35  $4.38 
         Net income – basic $9.02  $4.42 
         Net income – diluted $8.95  $4.39 
         
        Khanty Mansiysk Oil Corporation
        On May 12, 2003, Marathon acquired Khanty Mansiysk Oil Corporation (“KMOC”) for $285 million, including the assumption of $31 million in debt. KMOC is engaged in evaluating or developing nine oil fields in the Khanty-Mansiysk region of western Siberia in the Russian Federation. Results of operations for 2003 include the results of KMOC from May 12, 2003.
             The following unaudited pro forma data for Marathon includes the results of operations of KMOC giving effect to the acquisition as if it had been consummated at the beginning of the period presented. The pro forma data is based on historical information and does not necessarily represent the actual results that would have occurred nor is it necessarily indicative of future results of operations.
              
        (In millions, except per share amounts) 2003
         
        Revenues and other income $41,257 
        Income from continuing operations  1,005 
        Net income  1,314 
        Per share data:    
         Income from continuing operations – basic and diluted $3.24 
         Net income – basic and diluted $4.23 
         

        F-20


        6.7. Discontinued Operations
        On October 1, 2003, Marathon sold its exploration and production operations in western Canada for $612 million. This divestiture decision was made as part of Marathon’s strategic plan to rationalize noncore oil and gas properties. The results of these operations have been reported separately as discontinued operations in the consolidated statements of income. The sale resulted in a gain of $278 million, including a tax benefit of $8 million, which has been reported in discontinued operations. Revenues applicable to the discontinued operations totaled $188 million for 2003. Pretax income from discontinued operations was $66 million for 2003. During 2004, the final working capital adjustment was determined, which resulted in an additional gain of $4 million that is reported in discontinued operations.

                On June 2, 2006, Marathon sold its Russian oil exploration and production businesses in the Khanty-Mansiysk region of western Siberia. Under the terms of the agreement, Marathon received $787 million for these businesses, plus preliminary working capital and other closing adjustments of $56 million, for a total transaction value of $843 million. Proceeds net of transaction costs and cash held by the Russian businesses at the transaction date totaled $832 million. A gain on the sale of $243 million ($342 million before income taxes) was reported in discontinued operations for 2006. Income taxes on this gain were reduced by the utilization of a capital loss carryforward as discussed in Note 11. Exploration and Production segment goodwill of $21 million was allocated to the Russian assets and reduced the reported gain. The final adjustment to the sales price is expected to be made in 2007 and could affect the reported gain.

                The activities of the Russian businesses have been reported as discontinued operations in the consolidated statements of income and the consolidated statements of cash flows for all periods presented. Revenues applicable to discontinued operations were $173 million, $325 million and $133 million for 2006, 2005, and 2004. Pretax income from discontinued operations was $45 million and $61 million for 2006 and 2005. There was a pretax loss from discontinued operations of $45 million in 2004.

        F-19



        7.8. Income per Common Share

                                   
          2005 2004 2003
               
        (Dollars in millions, except per share data) Basic Diluted Basic Diluted Basic Diluted
         
        Income from continuing operations $3,051  $3,051  $1,257  $1,257  $1,012  $1,012 
        Income from discontinued operations  –    –    4   4   305   305 
        Cumulative effect of changes in accounting principles  (19)  (19)  –    –    4   4 
                           
        Net income $3,032  $3,032  $1,261  $1,261  $1,321  $1,321 
                           
        Shares of common stock outstanding (thousands):                        
          Average number of common shares outstanding  356,003   356,003   336,485   336,485   310,129   310,129 
          Effect of dilutive securities – stock options  –    3,078   –    1,768   –    197 
                           
          Average common shares including dilutive effect  356,003   359,081   336,485   338,253   310,129   310,326 
                           
        Per share:                        
         Income from continuing operations $8.57  $8.49  $3.74  $3.72  $3.26  $3.26 
                           
         Income from discontinued operations $–   $–   $0.01  $0.01  $0.99  $0.99 
                           
         Cumulative effect of changes in accounting principles $(0.05) $(0.05) $–   $–   $0.01  $0.01 
                           
         Net income $8.52  $8.44  $3.75  $3.73  $4.26  $4.26 

                Basic income per share is based on the weighted average number of common shares outstanding. Diluted income per share assumes exercise of stock options, provided the effect is not antidilutive.

         
         2006
         2005
         2004
         
        (Dollars in millions, except per share data)

         Basic
         Diluted
         Basic
         Diluted
         Basic
         Diluted
         

         
        Income from continuing operations $4,957 $4,957 $3,006 $3,006 $1,294 $1,294 
        Discontinued operations  277  277  45  45  (33) (33)
        Cumulative effect of change in accounting principle  –    –    (19) (19) –    –   
          
         
         
         
         
         
         
        Net income $5,234 $5,234 $3,032 $3,032 $1,261 $1,261 
          
         
         
         
         
         
         
        Weighted average common shares outstanding  357,911  357,911  356,003  356,003  336,485  336,485 
        Effect of dilutive securities  –    3,116  –    3,078  –    1,768 
          
         
         
         
         
         
         
        Weighted average common shares, including dilutive effect  357,911  361,027  356,003  359,081  336,485  338,253 
          
         
         
         
         
         
         
        Per share:                   
         Income from continuing operations $13.85 $13.73 $8.44 $8.37 $3.85 $3.83 
          
         
         
         
         
         
         
         Discontinued operations $0.77 $0.77 $0.13 $0.12 $(0.10)$(0.10)
          
         
         
         
         
         
         
         Cumulative effect of change in accounting principle $–   $–   $(0.05)$(0.05)$–   $–   
          
         
         
         
         
         
         
         Net income $14.62 $14.50 $8.52 $8.44 $3.75 $3.73 

         


        8.9. Segment Information

        Revenues by product line were:
                      
        (In millions) 2005 2004 2003
         
        Refined products $40,040  $29,780  $24,092 
        Merchandise  2,689   2,489   2,395 
        Liquid hydrocarbons  16,677   13,860   10,500 
        Natural gas  3,675   3,266   3,796 
        Transportation and other  230   203   180 
                  
         Total $63,311  $49,598  $40,963 
         
        Matching buy/sell transactions settled in cash by product line included above were:
                      
        (In millions) 2005 2004 2003
         
        Refined products $1,817  $1,226  $826 
        Liquid hydrocarbons  10,819   8,016   6,357 
                  
         Total $12,636  $9,242  $7,183 
         

        F-21        Revenues by product line were:

        (In millions)

         2006
         2005
         2004

        Refined products $45,511 $40,040 $29,780
        Merchandise  2,871  2,689  2,489
        Liquid hydrocarbons  12,531  16,352  13,727
        Natural gas  3,742  3,675  3,266
        Transportation and other  241  230  203
          
         
         
         Total $64,896 $62,986 $49,465

                Matching buy/sell transactions by product line included above were:

        (In millions)

         2006
         2005
         2004

        Refined products $645 $1,817 $1,226
        Liquid hydrocarbons  4,812  10,819  8,016
          
         
         
         Total $5,457 $12,636 $9,242

                Effective January 1, 2006, Marathon revised its measure of segment income to include the effects of minority interests and income taxes related to the segments to facilitate comparison of segment results with Marathon's peers. In addition, the results of activities primarily associated with the marketing of the Company's equity natural gas production, which had been presented as part of the IG segment prior to 2006, are now included in the E&P segment as those activities are aligned with E&P operations. Segment information for all periods presented reflects these changes.

                As discussed in Note 7, the Russian businesses that were sold in June 2006 have been accounted for as discontinued operations. Segment information for all presented periods excludes the amounts for these Russian operations.

        F-20


        (In millions)

         Exploration
        and
        Production

         Refining,
        Marketing and
        Transportation

         Integrated
        Gas

         Total
         

         
        2006             
        Revenues:             
         Customer $8,326 $54,471 $179 $62,976 
         Intersegment(a)  672  16  –    688 
         Related parties  12  1,454  –    1,466 
          
         
         
         
         
          Segment revenues  9,010  55,941  179  65,130 
         Elimination of intersegment revenues  (672) (16) –    (688)
         Gain on long-term U.K. natural gas contracts  454  –    –    454 
          
         
         
         
         
          Total revenues $8,792 $55,925 $179 $64,896 
          
         
         
         
         
        Segment income $2,003 $2,795 $16 $4,814 
        Income from equity method investments  206  145  40  391 
        Depreciation, depletion and amortization(b)  919  558  9  1,486 
        Minority interests in loss of subsidiaries  –    –    (10) (10)
        Income tax provision(b)  2,371  1,642  8  4,021 
        Capital expenditures(c)  2,169  916  307  3,392 

         
        2005             
        Revenues:             
         Customer $7,320 $54,414 $236 $61,970 
         Intersegment(a)  678  198  –    876 
         Related parties  11  1,391  –    1,402 
          
         
         
         
         
          Segment revenues  8,009  56,003  236  64,248 
         Elimination of intersegment revenues  (678) (198) –    (876)
         Loss on long-term U.K. natural gas contracts  (386) –    –    (386)
          
         
         
         
         
          Total revenues $6,945 $55,805 $236 $62,986 
          
         
         
         
         
        Segment income $1,887 $1,628 $55 $3,570 
        Income from equity method investments  69  137  59  265 
        Depreciation, depletion and amortization(b)  794  468  8  1,270 
        Minority interests in income (loss) of subsidiaries(b)  –    376  (8) 368 
        Income tax provision (benefit)(b)  1,030  1,007  (7) 2,030 
        Capital expenditures(c)  1,366  841  571  2,778 

         
        2004             
        Revenues:             
         Customer $5,888 $42,435 $190 $48,513 
         Intersegment(a)  516  152  –    668 
         Related parties  8  1,043  –    1,051 
          
         
         
         
         
          Segment revenues  6,412  43,630  190  50,232 
         Elimination of intersegment revenues  (516) (152) –    (668)
         Loss on long-term U.K. natural gas contracts  (99) –    –    (99)
          Total revenues $5,797 $43,478 $190 $49,465 
          
         
         
         
         
        Segment income $1,090 $568 $37 $1,695 
          
         
         
         
         
        Income from equity method investments  17  81  69  167 
        Depreciation, depletion and amortization(b)  724  416  7  1,147 
        Minority interests in income (loss) of subsidiaries(b)  –    539  (7) 532 
        Income tax provision(b)  606  301  19  926 
        Capital expenditures(c)  840  794  488  2,122 

         
        (a)
        Management believes intersegment transactions were conducted under terms comparable to those with unrelated parties.
        (b)
        Differences between segment totals and Marathon totals represent amounts related to corporate administrative activities and other unallocated items and are included in Items not allocated to segments, net of income taxes in the reconciliation below.
        (c)
        Differences between segment totals and Marathon totals represent amounts related to corporate administrative activities.

        F-21


             The following represents information by operating segment:

                           
          Exploration Refining,    
          and Marketing and Integrated  
        (In millions) Production Transportation Gas Total
         
        2005
                        
        Revenues:                
         Customer $6,009  $54,414  $1,872  $62,295 
         
        Intersegment(a)
          466   198   212   876 
         Related parties  11   1,391   –    1,402 
                     
          Segment revenues  6,486   56,003   2,084   64,573 
         Elimination of intersegment revenues  (466)  (198)  (212)  (876)
         Loss on long-term U.K. natural gas contracts  (386)  –    –    (386)
                     
          Total revenues $5,634  $55,805  $1,872  $63,311 
                     
        Segment income $2,988  $3,013  $31  $6,032 
        Income from equity method investments  67   137   62   266 
        Depreciation, depletion and amortization(b)
          849   468   9   1,326 
        Capital expenditures(c)
          1,460   841   572   2,873 
         
        2004
                        
        Revenues:                
         Customer $4,618  $42,435  $1,593  $48,646 
         
        Intersegment(a)
          370   152   146   668 
         Related parties  8   1,043   –    1,051 
                     
          Segment revenues  4,996   43,630   1,739   50,365 
         Elimination of intersegment revenues  (370)  (152)  (146)  (668)
         Loss on long-term U.K. natural gas contracts  (99)  –    –    (99)
                     
          Total revenues $4,527  $43,478  $1,593  $49,598 
                     
        Segment income $1,696  $1,406  $48  $3,150 
        Income from equity method investments  20   81   69   170 
        Depreciation, depletion and amortization(b)
          750   416   8   1,174 
        Capital expenditures(c)
          944   794   490   2,228 
         
        2003
                        
        Revenues:                
         Customer $4,460  $33,508  $2,140  $40,108 
         
        Intersegment(a)
          405   97   108   610 
         Related parties  12   909   –    921 
                     
          Segment revenues  4,877   34,514   2,248   41,639 
         Elimination of intersegment revenues  (405)  (97)  (108)  (610)
         Loss on long-term U.K. natural gas contracts  (66)  –    –    (66)
                     
          Total revenues $4,406  $34,417  $2,140  $40,963 
                     
        Segment income $1,580  $819  $(3) $2,396 
        Income from equity method investments(d)
          50   82   21   153 
        Depreciation, depletion and amortization(b)
          724   375   12   1,111 
        Capital expenditures(c)
          973   789   131   1,893 
         
        (a)Management believes intersegment transactions were conducted under terms comparable to those with unrelated parties.
        (b)Differences between segment totals and Marathon totals represent impairments and amounts related to corporate administrative activities and are included in administrative expenses in the reconciliation below.
        (c)Differences between segment totals and Marathon totals represent amounts related to corporate administrative activities.
        (d)Excludes a $124 million loss on the dissolution of MKM Partners L.P., which was not allocated to segments. See Note 13.

        F-22        The following reconciles segment income to net income as reported in the consolidated statements of income.

        (In millions)

         2006
         2005
         2004
         

         
        Segment income $4,814 $3,570 $1,695 
        Items not allocated to segments, net of income taxes:          
         Corporate and other unallocated items  (212) (377) (327)
         Gain (loss) on long-term U.K. natural gas contracts  232  (223) (57)
         Discontinued operations  277  45  (33)
         Gain on disposition of Syria interest  31  –    –   
         Deferred income taxes – tax legislation changes  21  15  –   
                                                  0; other adjustments(a)  93  –    –   
         Loss on early extinguishment of debt  (22) –    –   
         Gain on sale of minority interests in EGHoldings  –    21  –   
         Corporate insurance adjustment  –    –    (17)
         Cumulative effect of change in accounting principle  –    (19) –   
          
         
         
         
          Net income $5,234 $3,032 $1,261 

         
        (a)
        Other deferred tax adjustments in 2006 represent a benefit recorded for cumulative income tax basis differences associated with prior periods.


                The following summarizes revenues from external customers by geographic area.

        (In millions)

         2006
         2005
         2004

        United States $59,723 $60,242 $47,354
        International  5,173  2,744  2,111
          
         
         
         Total $64,896 $62,986 $49,465

                The following summarizes certain long-lived assets by geographic area, including property, plant and equipment and investments.

        (In millions)

         2006
         2005

        United States $11,401 $10,143
        Equatorial Guinea  3,157  3,018
        Other international  3,668  3,510
          
         
         Total $18,226 $16,671

             The following reconciles segment income to income from operations as reported in the consolidated statements of income:

                       
        (In millions) 2005 2004 2003
         
        Segment income $6,032  $3,150  $2,396 
        Items not allocated to segments:            
         Administrative expenses  (367)  (307)  (227)
         Losses on long-term U.K. natural gas contracts  (386)  (99)  (66)
         Gain on sale of minority interests in EGHoldings  23   –    –  
         Impairment of certain oil and gas properties  –    (44)  –  
         Corporate insurance adjustment  –    (32)  –  
         Gain on asset disposition  –    –    106 
         Loss on dissolution of MKM Partners L.P.  –    –    (124)
         Gain (loss) on ownership changes in subsidiaries  –    2   (1)
                  
          Income from operations $5,302  $2,670  $2,084 
         
             The information below summarizes the operations in different geographic areas. Transfers between affiliates are at prices that approximate market.
                             
            Revenues  
               
            From Unaffiliated From    
        (In millions) Year Customers Affiliates Total Assets(a)
         
        United States  2005  $60,242  $6  $60,248  $10,143 
           2004   47,354   –    47,354   8,396 
           2003   39,377   –    39,377   8,061 
        United Kingdom  2005  $1,569  $64  $1,633  $984 
           2004   995   –    995   1,076 
           2003   849   –    849   1,215 
        Equatorial Guinea  2005  $45  $598  $643  $3,018 
           2004   247   –    247   2,444 
           2003   119   –    119   1,656 
        Other Foreign Countries  2005  $1,455  $2,126  $3,581  $2,526 
           2004   1,002   1,868   2,870   1,231 
           2003   618   1,352   1,970   1,073 
        Eliminations  2005  $–   $(2,794) $(2,794) $–  
           2004   –    (1,868)  (1,868)  –  
           2003   –    (1,352)  (1,352)  –  
        Total  2005  $63,311  $–   $63,311  $16,671 
           2004   49,598   –    49,598   13,147 
           2003   40,963   –    40,963   12,005 
         
        (a)Includes property, plant and equipment and investments.

        9.10. Other Items

        Net interest and other financing costs (income)

                       
        (In millions) 2005 2004 2003
         
        Interest and other financial income:
                    
         Interest income $78  $45  $16 
         Foreign currency adjustments  (17)  9   13 
                  
          Total  61   54   29 
                  
        Interest and other financing costs:
                    
         
        Interest incurred(a)
          257   262   282 
         Less income from interest rate swaps  –    24   23 
         Less interest capitalized  83   48   41 
                  
          Net interest expense  174   190   218 
         Interest on tax issues  22   12   (13)
         Other  10   13   10 
                  
          Total  206   215   215 
                  
        Net interest and other financing costs
         $145  $161  $186 
         
        (a)Excludes $34 million, $40 million and $34 million paid by United States Steel in 2005, 2004 and 2003 on assumed debt.

        (In millions)

         2006
         2005
         2004
         

         
        Interest and other financial income:          
         Interest income $129 $77 $44 
         Foreign currency gains (losses)  16  (17) 9 
          
         
         
         
          Total  145  60  53 
          
         
         
         
        Interest and other financing costs:          
         Interest incurred(a)  245  257  262 
         (Income) loss from interest rate swaps  16  –    (24)
         Interest capitalized  (152) (83) (48)
          
         
         
         
          Net interest expense  109  174  190 
         Net interest expense (income) on tax issues  (11) 22  12 
         Other  10  10  13 
          
         
         
         
          Total  108  206  215 
          
         
         
         
        Net interest and other financing costs (income) $(37)$146 $162 

         
        (a)
        Excludes $33 million, $34 million and $40 million paid by United States Steel in 2006, 2005 and 2004 on assumed debt.

        F-23


        Foreign currency transactions
        Aggregate foreign currency losses were included in the consolidated statements of income as follows:
                      
        (In millions) 2005 2004 2003
         
        Net interest and other financing costs $(17) $9  $13 
        Provision for income taxes  (24)  (15)  (15)
                  
         Aggregate foreign currency losses $(41) $(6) $(2)
          –  Aggregate foreign currency gains (losses) were included in the consolidated statements of income as follows:

        (In millions)

         2006
         2005
         2004
         

         
        Net interest and other financing costs $16 $(17)$9 
        Provision for income taxes  (22) 24  (15)
          
         
         
         
         Aggregate foreign currency gains (losses) $(6)$7 $(6)

         

        F-22



        10.11. Income Taxes

        Provisions (credits) for income taxes were:
                                              
          2005 2004 2003
               
        (In millions) Current Deferred Total Current Deferred Total Current Deferred Total
         
        Federal $1,227  $16  $1,243  $473  $(22) $451  $280  $95  $375 
        State and local  171   12   183   47   1   48   56   (4)  52 
        Foreign  540   (236)  304   280   (52)  228   177   (20)  157 
                                    
         Total $1,938  $(208) $1,730  $800  $(73) $727  $513  $71  $584 
         
             A reconciliation of the federal statutory tax rate (35 percent) applied to income before income taxes to the total provisions for income taxes follows:
                      
        (In millions) 2005 2004 2003
         
        Statutory rate applied to income before income taxes $1,673  $694  $559 
        Effects of foreign operations, including foreign tax credits  (44)  26   (7)
        State and local income taxes after federal income tax effects  119   32   35 
        Credits other than foreign tax credits  (2)  (2)  (6)
        Domestic production activities deduction(a)
          (39)  –    –  
        Excess capital losses generated (utilized)  23   (4)  –  
        Effects of partially owned companies  (4)  (3)  (6)
        Adjustment of prior years’ federal income taxes  10   (11)  17 
        Other  (6)  (5)  (8)
                  
         Total provisions for income taxes $1,730  $727  $584 
         
        (a)See Note 2 regarding Marathon’s adoption of FSP No. FAS 109-1. Marathon has treated the deduction, equal to 3 percent of qualified production activities income for 2005 under the American Jobs Creation Act of 2004, as a special deduction.

        F-24        Income tax provisions (benefits) were:

         
         2006
         2005
         2004
        (In millions)

         Current
         Deferred
         Total
         Current
         Deferred
         Total
         Current
         Deferred
         Total

        Federal $1,579 $72 $1,651 $1,225 $14 $1,239 $476 $(20)$456
        State and local  230  30  260  171  12  183  47  1  48
        Foreign  1,945  166  2,111  523  (231) 292  274  (43) 231
          
         
         
         
         
         
         
         
         
         Total $3,754 $268 $4,022 $1,919 $(205)$1,714 $797 $(62)$735

                A reconciliation of the federal statutory tax rate (35 percent) applied to income from continuing operations before income taxes to the provision for income taxes follows:

        (In millions)

         2006
         2005
         2004
         

         
        Statutory rate applied to income from continuing operations before income taxes $3,143 $1,652 $710 
        Effects of foreign operations, including foreign tax credits(a)  888  (39) 10 
        State and local income taxes net of federal income tax effects  170  119  32 
        Credits other than foreign tax credits  (2) (2) (2)
        Domestic manufacturing deduction(b)  (47) (39) –   
        Excess capital losses generated (utilized)  –    23  (4)
        Effects of partially owned companies  (6) (4) (3)
        Adjustment of prior years' federal income taxes(c)  (119) 10  (8)
        Other  (5) (6) –   
          
         
         
         
         Provision for income taxes $4,022 $1,714 $735 

         
        (a)
        In 2006, Marathon resumed operations in Libya where the statutory income tax rate is in excess of 90 percent.
        (b)
        See Note 2 regarding Marathon's adoption of FSP No. FAS 109-1. Marathon has treated the deduction, equal to 3 percent of "qualified production activities income" under the American Jobs Creation Act of 2004, as a special deduction beginning in 2005.
        (c)
        The 2006 adjustment of prior years' federal income taxes is primarily related to a $93 million credit recorded in the fourth quarter of 2006 as a result of a deferred tax analysis of the tax consequences attributable to prior years' differences between the financial statement carrying amounts of assets and liabilities and their tax bases for U.S. federal income tax purposes.

                Deferred tax assets and liabilities resulted from the following:

        (In millions)

         December 31
         2006
         2005
         

         
        Deferred tax assets:         
         Employee benefits   $730 $622 
         Capital loss carryforwards(a)    –    79 
         Operating loss carryforwards(b)    1,016  754 
         Derivative instruments    81  181 
        Foreign tax credits(c)    527  123 
         Other    200  380 
         Valuation allowances         
          Federal(a)(d)    (19) (120)
          State(b)    (59) (72)
          Foreign(e)    (611) (435)
            
         
         
           Total deferred tax assets    1,865  1,512 
            
         
         
        Deferred tax liabilities:         
         Property, plant and equipment    2,951  2,867 
         Inventories    708  762 
         Investments in subsidiaries and affiliates    552  93 
         Other    100  108 
            
         
         
          Total deferred tax liabilities    4,311  3,830 
            
         
         
           Net deferred tax liabilities   $2,446 $2,318 

         
        (a)
        Capital loss carryforwards were utilized in conjunction with the sale of Marathon's Russian oil exploration and production businesses in June 2006 as discussed in Note 7. The reversal of the related valuation allowance reduced income taxes attributable to discontinued operations by $79 million.
        (b)
        For 2006, foreign operating loss carryforwards primarily include $684 million for Norway regular income tax, $1.006 billion for Norway special petroleum tax and $250 million for Angola income tax. The Norway and Angola operating loss carryforwards have no expiration dates. The remainder of foreign carryforwards are in several other foreign jurisdictions and expire in 2007 through 2019. State operating loss carryforwards of $1.352 billion expire in 2007 through 2021. The state operating loss carryforwards primarily relate the period prior to the Separation and are offset by valuation allowances.
        (c)
        Marathon expects to generate sufficient future taxable income to realize these credits. The ability to realize the benefit of foreign tax credits is based on certain assumptions concerning future operating conditions (particularly as related to prevailing commodity prices), income generated from foreign sources and Marathon's tax profile in the years that such credits may be claimed.
        (d)
        Federal valuation allowances increased by $63 million in 2005 and decreased by $10 million in 2004. The 2005 increase reflected valuation allowances established for deferred tax assets generated in 2005, primarily related to Marathon's re-entry into Libya of $38 million and excess capital losses related to certain derivative instruments and an asset sale of $30 million.
        (e)
        Foreign valuation allowances increased by $176 million, $70 million and $82 million in 2006, 2005 and 2004 primarily as a result of net operating loss carryforwards generated in those years in Norway, Angola and several other jurisdictions.

        F-23


                Net deferred tax liabilities were classified in the consolidated balance sheet as follows:

        (In millions)

         December 31
         2006
         2005

        Assets:        
         Other current assets   $4 $14
         Other noncurrent assets    78  148
        Liabilities:        
         Current deferred income taxes    631  450
         Noncurrent deferred income taxes    1,897  2,030
            
         
          Net deferred tax liabilities   $2,446 $2,318

                Marathon is continuously undergoing examination of its federal income tax returns by the Internal Revenue Service. Audits of the Company's 1998 through 2003 income tax returns have been completed and agreed upon by all parties. A $46 million refund was received from the 1998 through 2001 audit, $35 million of which was paid to United States Steel in accordance with the tax sharing agreement discussed in Note 3. The audit for tax years 2004 and 2005 commenced in May 2006. Marathon believes it has made adequate provision for federal income taxes and interest which may become payable for years not yet settled. Further, the Company is routinely involved in state and local income tax audits and foreign jurisdiction tax audits. Marathon believes all other audits will be resolved within the amounts paid and/or provided for these liabilities.

                Pretax income from continuing operations included amounts attributable to foreign sources of $3.570 billion in 2006, $1.061 billion in 2005 and $579 million in 2004.

                Undistributed income of certain consolidated foreign subsidiaries at December 31, 2006 amounted to $1.581 billion for which no deferred U.S. income tax provision has been made because Marathon intends to permanently reinvest such income in those foreign operations. If such income was not permanently reinvested, a tax expense of $554 million would have been incurred.


        12. Business Transformation

                During 2003, Marathon implemented an organizational realignment plan that included streamlining Marathon's business processes and services, realigning reporting relationships to reduce costs across all organizations, consolidating organizations in Houston, Texas and reducing the workforce. During 2004, Marathon entered into two outsourcing agreements to achieve further business process improvements and cost reductions.

                During 2004, Marathon recorded $43 million of costs as general and administrative expenses related to these business transformation programs. These charges included employee severance and benefit costs, relocation costs and net benefit plans settlement and curtailment losses.

                There were minimal charges to expense during 2005. As of December 31, 2005, no accrual remained related to the business transformation programs. The following table sets forth the significant components and activity in the business transformation programs during 2004.

        (In millions)

         Accrued
        January 1

         Expense
         Noncash
        Charges

         Cash
        Payments

         Accrued
        December 31


        Employee severance and termination benefits $12 $15 $–   $24 $3
        Net benefit plans settlement and curtailment losses  –    20  20  –    –  
        Relocation costs  5  8  –    11  2
        Fixed asset related costs  1  –    –    1  –  
          
         
         
         
         
         Total $18 $43 $20 $36 $5


        13. Inventories

        (In millions)

         December 31
         2006
         2005

        Liquid hydrocarbons and natural gas   $1,136 $1,093
        Refined products and merchandise    1,812  1,763
        Supplies and sundry items    225  185
            
         
         Total (at cost)   $3,173 $3,041

                The LIFO method accounted for 90 percent and 92 percent of total inventory value at December 31, 2006 and 2005. Current acquisition costs were estimated to exceed the LIFO inventory values at December 31, 2006 and 2005 by $1.682 billion and $1.535 billion.

        F-24


             Deferred tax assets and liabilities resulted from the following:
                     
        (In millions)December 312005 2004
         
        Deferred tax assets:
                
         Net operating loss carryforwards $–   $2 
         Capital loss carryforwards (expiring in 2008 and 2010)  79   57 
         State tax loss carryforwards (expiring in 2006 through 2021)  105   122 
         
        Foreign tax loss carryforwards(a)
          649   581 
         Expected federal benefit for:        
          Crediting certain foreign deferred income taxes  123   292 
          Deducting state and foreign deferred income taxes  183   37 
         Employee benefits  678   341 
         Contingencies and other accruals  295   201 
         Derivative instruments  196   40 
         Investments in subsidiaries and equity method investees  –    4 
         Other  101   86 
         
        Valuation allowances(b):
                
          Federal  (120)  (57)
          State  (72)  (71)
          Foreign  (435)  (365)
               
           
        Total deferred tax assets(c)
          1,782   1,270 
               
        Deferred tax liabilities:
                
         Property, plant and equipment  3,072   2,174 
         Inventory  775   304 
         Investments in subsidiaries and equity method investees  94   –  
         Prepaid pensions  47   70 
         Other  112   88 
               
           Total deferred tax liabilities  4,100   2,636 
               
            Net deferred tax liabilities $2,318  $1,366 
         
        (a)For 2005, includes $547 million for Norway and $54 million for Angola, both of which have no expiration dates. The remainder expire 2006 through 2019.
        (b)Valuation allowances related to federal deferred tax assets are associated with capital loss carryforwards. The remaining valuation allowances are primarily associated with net operating loss carryforwards in several state jurisdictions, Norway, Angola and several other foreign jurisdictions.
        (c)Marathon expects to generate sufficient future taxable income to realize the benefit of the deferred tax assets. In addition, the ability to realize the benefit of foreign tax credits is based on certain assumptions concerning future operating conditions (particularly as related to prevailing oil prices), income generated from foreign sources and Marathon’s tax profile in the years that such credits may be claimed.
             Net deferred tax liabilities were classified in the consolidated balance sheet as follows:
                   
        (In millions)December 312005 2004
         
        Assets:        
         Other current assets $14  $127 
         Other noncurrent assets  148   60 
        Liabilities:        
         Current deferred income taxes  450   –  
         Noncurrent deferred income taxes  2,030   1,553 
               
          Net deferred tax liabilities $2,318  $1,366 
         
             Marathon is continuously undergoing examination of its federal income tax returns by the Internal Revenue Service (“IRS”). Marathon and the IRS have settled tax years through 1997 and Marathon is in appeals for tax years 1998 through 2001. Audits for the tax years 2002 and 2003 are in progress and audits for tax years 2004 and 2005 will commence in 2006. Marathon believes it has made adequate provision for federal income taxes and interest which may become payable for years not yet settled. Further, the Company is routinely involved in state and local income tax audits, and on occasion, foreign jurisdiction tax audits. Marathon believes all other audits will be resolved within the amounts paid and/or provided for these liabilities.
             Pretax income from continuing operations included amounts attributable to foreign sources of $1.127 billion in 2005, $534 million in 2004 and $453 million in 2003.
             Undistributed income of certain consolidated foreign subsidiaries at December 31, 2005 amounted to $1.544 billion for which no deferred U.S. income tax provision has been made because Marathon intends to permanently reinvest such income in those foreign operations. If such income was not permanently reinvested, a deferred tax liability of $541 million would have been required.
             See Note 3 for a discussion of the Tax Sharing Agreement between Marathon and United States Steel.

        F-25



        11. Business Transformation
        During 2003, Marathon implemented an organizational realignment plan that included streamlining Marathon’s business processes and services, realigning reporting relationships to reduce costs across all organizations, consolidating organizations in Houston, Texas and reducing the workforce. During 2004, Marathon entered into two outsourcing agreements to achieve further business process improvements and cost reductions.
             During 2004 and 2003, Marathon recorded $43 million and $24 million of costs as general and administrative expenses related to these business transformation programs. These charges included employee severance and benefit costs related to the elimination of approximately 700 regular employee positions, relocation costs, net benefit plans settlement and curtailment losses and fixed asset related costs.
             There were minimal charges to expense during 2005 and, as of December 31, 2005, no accrual remained related to the business transformation programs. The following table sets forth the significant components and activity in the business transformation programs during 2004 and 2003.
                              
          Accrued   Noncash Cash Accrued
        (In millions) January 1 Expense Charges (Gains) Payments December 31
         
        2004
                            
        Employee severance and termination benefits $12  $15  $–   $24  $3 
        Net benefit plans settlement and curtailment losses  –    20   20   –    –  
        Relocation costs  5   8   –    11   2 
        Fixed asset related costs  1   –    –    1   –  
                        
         Total $18  $43  $20  $36  $5 
         
        2003
                            
        Employee severance and termination benefits $–   $25  $–   $13  $12 
        Net benefit plans settlement and curtailment gains  –    (10)  (10)  –    –  
        Relocation costs  –    5   –    –    5 
        Fixed asset related costs  –    4   2   1   1 
                        
         Total $–   $24  $(8) $14  $18 
         
        12. Inventories
                   
        (In millions)December 31  2005 2004
         
        Liquid hydrocarbons and natural gas  $1,093  $676 
        Refined products and merchandise   1,763   1,192 
        Supplies and sundry items   185   127 
                
         Total (at cost)  $3,041  $1,995 
         
             The LIFO method accounted for 92 percent of total inventory value at December 31, 2005 and 2004. Current acquisition costs were estimated to exceed the LIFO inventory values at December 31, 2005 and 2004 by approximately $1,535 million and $1,294 million. Cost of revenues and income from operations showed no change in 2005 as a result of liquidations of LIFO inventories. Cost of revenues was reduced and income from operations was increased by $4 million in 2004, and $11 million in 2003 as a result of liquidations of LIFO inventories.

        F-26


        13.14. Investments and Long-Term Receivables
                   
        (In millions)December 312005 2004
         
        Equity method investments:        
         Alba Plant LLC $513  $432 
         Atlantic Methanol Production Company LLC  258   265 
         Pilot Travel Centers LLC  516   372 
         LOOP LLC  148   60 
         Other  220   205 
        Other investments  5   3 
        Recoverable environmental costs receivable  57   52 
        Value-added tax refunds receivable  29   32 
        Fair value of derivative assets  14   24 
        Deposits of restricted cash  87   89 
        Other receivables  17   12 
               
          Total $1,864  $1,546 
         
             Summarized financial information of investees accounted for by the equity method of accounting follows:
                      
        (In millions) 2005 2004 2003
         
        Income data – year:            
         Revenues and other income $10,088  $7,419  $7,036 
         Operating income  556   434   435 
         Net income  474   330   319 
         
        Balance sheet data – December 31:            
         Current assets $645  $583     
         Noncurrent assets  3,598   3,990     
         Current liabilities  668   569     
         Noncurrent liabilities  1,477   1,511     
         
             Marathon’s carrying value of its equity method investments is $643

        (In millions)

         December 31
         2006
         2005

        Equity method investments:        
         Alba Plant LLC   $420 $513
         Atlantic Methanol Production Company LLC    257  258
         Pilot Travel Centers LLC    510  516
         LOOP LLC    156  148
         Other    196  220
        Other investments    34  5
        Recoverable environmental costs receivable    54  57
        Value-added tax refunds receivable    –    29
        Fair value of derivative assets    –    14
        Deposits of restricted cash    240  87
        Other receivables    20  17
            
         
          Total   $1,887 $1,864

                Summarized financial information of investees accounted for by the equity method of accounting follows:

        (In millions)

         2006
         2005
         2004

        Income data – year:         
         Revenues and other income $11,873 $10,088 $7,419
         Operating income  746  556  434
         Net income  710  474  330

        Balance sheet data – December 31:         
         Current assets $817 $645   
         Noncurrent assets  3,637  3,598   
         Current liabilities  755  668   
         Noncurrent liabilities  1,119  1,477   

                Marathon's carrying value of its equity method investments is $250 million higher than the underlying net assets of investees. This basis difference is being amortized into net income over the remaining useful lives of the underlying net assets except for $144 million of the excess related to goodwill.

             Dividends and partnership distributions received from equity method investees (excluding distributions that represented a return of capital previously contributed) were $200 million in 2005, $152 million in 2004, and $175 million in 2003.
             On June 30, 2003, Marathon and Kinder Morgan Energy Partners, L.P. (“Kinder Morgan”) dissolved MKM Partners L.P. which had oil and gas production operations in the Permian Basin of Texas. Marathon held an 85 percent noncontrolling interest in the partnership. Prior to the dissolution of the partnership, Kinder Morgan acquired MKM Partners L.P.’s 12.75 percent interest in the SACROC unit for an undisclosed amount. The partnership recorded a loss on the disposal of SACROC of $19 million, of which Marathon’s share was $17 million. Also prior to the dissolution, Marathon recorded a $107 million impairment of its investment in MKM Partners L.P. due to an other-than-temporary decline in the fair value of the investment. The total loss recognized by Marathon related to the dissolution of MKM Partners L.P. was $124 million. The partnership’s interest in the Yates field was distributed to Marathon and Kinder Morgan on dissolution.

        F-27        Dividends and partnership distributions received from equity method investees (excluding distributions that represented a return of capital previously contributed) were $191 million in 2006, $200 million in 2005 and $152 million in 2004.



        14.15. Property, Plant and Equipment
                  
        (In millions)December 31 2005 2004
         
        Production $17,262  $15,162 
        Refining  4,727   4,398 
        Marketing  1,895   1,954 
        Transportation  1,980   1,816 
        Gas liquefaction  1,067   524 
        Other  464   382 
               
         Total  27,395   24,236 
               
        Less accumulated depreciation, depletion and amortization  12,384   12,426 
               
         Net property, plant and equipment $15,011  $11,810 
         
             Property, plant and equipment includes gross assets acquired under capital leases of $78 million and $49 million at December 31, 2005 and 2004, with related amounts in accumulated depreciation, depletion and amortization of $6 million and $6 million at December 31, 2005 and 2004.
             Deferred exploratory well costs were as follows:
                      
        (Dollars in millions)December 31 2005 2004 2003
         
        Amounts capitalized less than one year after completion of drilling $304  $284  $165 
        Amounts capitalized greater than one year after completion of drilling  59   55   78 
                  
         Total deferred exploratory well costs $363  $339  $243 
         
        Number of projects with costs capitalized for greater than one year after completion of drilling  2   2   4 
         
             Exploratory well costs capitalized greater than one year after completion of drilling as of December 31, 2005 included $43 million for the Ozona prospect that was primarily incurred in 2001 and 2002 and $16 million for the Flathead prospect that was primarily incurred in 2001. Both prospects are located in the Gulf of Mexico. Marathon’s plans are to develop the Ozona prospect as a subsea tieback to area infrastructure. Commercial terms have been secured for the tieback and processing of Ozona production and Marathon is attempting to secure a drilling rig to drill the development well. Technical evaluations on the Flathead prospect continued during 2005 and are progressing towards a potential re-entry and sidetrack well before 2008. In 2005, a well drilled on a block directly offsetting the Flathead prospect encountered hydrocarbons.
             The net changes in deferred exploratory well costs were as follows:
                                 
          Balance at     Transfer to   Balance
          Beginning of   Dry Well Proved   at End
        (In millions) Period Additions Expense Properties Other of Period
         
        Year ended December 31, 2005
         $339  $135  $(31) $(80) $   $363 
        Year ended December 31, 2004  243   239   (54)  (89)  –    339 
        Year ended December 31, 2003  148   256   (56)  (90)  (15)(a)  243 
         
        (a)Related to the sale of Marathon’s exploration and production operations in Western Canada.

        (In millions)

         December 31
         2006
         2005

        Production   $18,894 $17,262
        Refining    5,238  4,727
        Marketing    2,015  1,895
        Transportation    2,173  1,980
        Gas liquefaction    1,321  1,067
        Other    585  464
            
         
         Total    30,226  27,395
            
         
        Less accumulated depreciation, depletion and amortization    13,573  12,384
            
         
         Net property, plant and equipment   $16,653 $15,011

                Property, plant and equipment includes gross assets acquired under capital leases of $79 million and $78 million at December 31, 2006 and 2005, with related amounts in accumulated depreciation, depletion and amortization of $10 million and $6 million at December 31, 2006 and 2005.

        F-28F-25


                Deferred exploratory well costs were as follows:

        (Dollars in millions)                                                                                                              December 31
         2006
         2005
         2004

        Amounts capitalized less than one year after completion of drilling $377 $304 $284
        Amounts capitalized greater than one year after completion of drilling  93  59  55
          
         
         
         Total deferred exploratory well costs $470 $363 $339
          
         
         
        Number of projects with costs capitalized greater than one year after completion of drilling  3  2  2

                Exploratory well costs capitalized greater than one year after completion of drilling as of December 31, 2006 included $46 million for the Ozona prospect that was primarily incurred in 2001 and 2002, $17 million for the Flathead prospect that was primarily incurred in 2001 and $30 million related to wells in Equatorial Guinea (primarily Corona and Gardenia) that was primarily incurred in 2004. Both Ozona and Flathead are located in the Gulf of Mexico.


                Marathon is continuing to evaluate options to develop the Ozona Prospect. Commercial terms were secured in 2005 after protracted negotiations with offset operators to allow this sub-sea well to be tied back to existing oil and gas infrastructure. A sidetrack well was planned for 2006; however, a deepwater rig could not be obtained due to a partner disposition of interest in the prospect and a shortage of deepwater rigs resulting from hurricane damage in 2005 and increased deepwater drilling activity. During 2006, Marathon continued its efforts to advance the Ozona Prospect by reprocessing existing seismic data to optimize the next well location. Marathon has also continued to actively search for rig availability.

                Technical evaluations are complete on the Flathead Prospect and commercial evaluations continued in 2006. The drilling of this prospect is delayed due to the shortage of available deepwater rigs. Marathon continues to pursue partnering opportunities with other oil and gas companies with deepwater rigs under contract that will ultimately result in a well being drilled by 2008.

        15. Goodwill
        The changes in the carrying amount of goodwill for the years ended December 31, 2005 and 2004, are as follows:
                      
          Exploration Refining, Marketing  
          and and  
        (In millions) Production Transportation Total
         
        Balance as of January 1 and December 31, 2004 $231  $21  $252 
         
        Goodwill acquired
          315   735   1,050 
         
        Other
          –    5   5 
                  
        Balance as of December 31, 2005
         $546  $761  $1,307 
         
             The E&P segment tests goodwill for impairment in the second quarter of each year. The RM&T segment tests goodwill for impairment in the fourth quarter of each year. No impairment in the carrying value of goodwill has been identified.
                The Equatorial Guinea discovery wells will be part of Marathon's long-term LNG sales strategy. These resources will be developed when the natural gas supply from the nearby Alba Fields starts to decline or additional LNG markets are obtained that require increased natural gas supply.

                The net changes in deferred exploratory well costs were as follows:

        (In millions)

         Balance at
        Beginning of
        Period

         Additions
         Dry Well
        Expense

         Transfer to
        Proved
        Properties

         Disposals
         Balance
        at End of
        Period


        Year ended December 31, 2006 $363 $174 $(27)$(21)$(19)$470
        Year ended December 31, 2005  339  135  (31) (80) –    363
        Year ended December 31, 2004  243  239  (54) (89) –    339

        F-26



        16. Goodwill

        The changes in the carrying amount of goodwill for the years ended December 31, 2006 and 2005, were as follows:

        (In millions)

         Exploration
        and
        Production

         Refining, Marketing
        and
        Transportation

         Total
         

         
        Balance as of December 31, 2004 $231 $21 $252 
         Goodwill acquired  315  735  1,050 
         Other  –    5  5 
          
         
         
         
        Balance as of December 31, 2005  546  761  1,307 
         Adjustments to previously acquired goodwill  (6) 118(a) 112 
         Disposals(b)  (21) –    (21)
          
         
         
         
        Balance as of December 31, 2006 $519 $879 $1,398 

         
        (a)
        Reflects adjustments related to additional consideration payable and prior period income tax adjustments.
        (b)
        Exploration and Production segment goodwill allocated to the Russian businesses that were sold in June 2006 as discussed in Note 7.

                The E&P segment tests goodwill for impairment in the second quarter of each year. The RM&T segment tests goodwill for impairment in the fourth quarter of each year. No impairment in the carrying value of goodwill has been identified.


        17. Intangible Assets

        Intangible assets are as follows:
                       
          Gross   Net
          Carrying Accumulated Carrying
        (In millions)December 31 Amount Amortization Amount
         
        2005
                    
        Amortized intangible assets:            
         Branding agreements $51  $16  $35 
         Elba Island delivery rights  42   6   36 
         Other  96   36   60 
                  
          Total $189  $58  $131 
                  
        Unamortized intangible assets:            
         Retail marketing tradenames $49  $–   $49 
         Unrecognized prior service costs and other  20   –    20 
                  
          Total $69  $–   $69 
         
        2004
                    
        Amortized intangible assets:            
         Branding agreements $53  $19  $34 
         Elba Island delivery rights  42   5   37 
         Other  49   27   22 
                  
          Total $144  $51  $93 
                  
        Unamortized intangible assets:            
         Unrecognized prior service costs and other $25  $–   $25 
         
             Amortization expense related to intangibles during 2005, 2004 and 2003 totaled $16 million, $7 million and $12 million. Estimated amortization expense for the years 2006-2010 is $20 million, $15 million, $13 million, $12 million and $11 million.

        F-29Intangible assets were as follows:

        (In millions)                                                 December 31
         Gross Carrying
        Amount

         Accumulated
        Amortization

         Net Carrying
        Amount


        2006         
        Amortized intangible assets:         
         Branding agreements $54 $20 $34
         Elba Island delivery rights  42  8  34
         Other  103  47  56
          
         
         
          Total $199 $75 $124
          
         
         
        Unamortized intangible assets:         
         Retail marketing tradenames $49 $–   $49
         Other  7  –    7
          
         
         
          Total $56 $–   $56

        2005         
        Amortized intangible assets:         
         Branding agreements $51 $16 $35
         Elba Island delivery rights  42  6  36
         Other  96  36  60
          
         
         
          Total $189 $58 $131
          
         
         
        Unamortized intangible assets:         
         Retail marketing tradenames $49 $–   $49
         Unrecognized prior service costs and other  20  –    20
          
         
         
          Total $69 $–   $69

                Amortization expense related to intangibles during 2006, 2005 and 2004 totaled $19 million, $16 million and $7 million. Estimated amortization expense for the years 2007-2011 is $16 million, $14 million, $13 million, $12 million and $10 million.

        F-27



        17.18. Derivative Instruments
        The following table sets forth quantitative information by category of derivative instrument at December 31, 2005 and 2004. These amounts are reported on a gross basis by individual derivative instrument.
                           
          2005 2004
             
        (In millions)  December 31 Assets(a) (Liabilities)(a) Assets(a) (Liabilities)(a)
         
        Commodity Instruments
                        
         
        Fair value hedges(b):
                        
          Exchange traded commodity futures $2  $(2) $2  $(1)
          Over-the-counter (“OTC”) commodity swaps  66   (2)  27   –  
         Non-hedge designation:                
          Exchange-traded commodity futures $281  $(288) $222  $(210)
          Exchange-traded commodity options  70   (65)  79   (65)
          OTC commodity swaps  105   (99)  101   (61)
          OTC commodity options  3   (6)  5   (4)
        Nontraditional Instruments
                        
          
        United Kingdom long-term natural gas contracts(d)
         $–   $(513) $–   $(127)
          
        Physical commodity contracts(e)
          71   (62)  86   (91)
        Financial Instruments
                        
         Fair value hedges:                
          
        OTC interest rate swaps(f)
         $–   $(30) $2  $(12)
         
        Cash flow hedges(c):
                        
          OTC foreign currency swaps  –    (2)  10   (1)
         
        (a)The fair value and carrying value of derivative instruments are the same. The fair values for OTC positions are determined using option-pricing models or dealer quotes. The fair values of exchange-traded positions are based on market quotes derived from major exchanges. The fair value of interest rate and foreign currency swaps is based on dealer quotes. Marathon’s consolidated balance sheet is reported on a net asset/(liability) basis by brokerage firm, as permitted by the master netting agreements.
        (b)There was no ineffectiveness associated with fair value hedges for 2005 or 2004 because the hedging instruments and the existing firm commitment contracts are priced on the same underlying index. Certain derivative instruments used in the fair value hedges mature between 2006 and 2008.
        (c)The ineffective portion of changes in the fair value for cash flow hedges, on a before tax basis, was less than $1 million during 2005 and $1 million during 2004. In addition, during 2004, losses of $3 million were recognized in revenues as the result of a discontinuation of a portion of a cash flow hedge related to natural gas and crude oil production. There were no losses recorded in 2005 relating to a discontinuation. Of the unrealized gains and losses recorded in accumulated other comprehensive loss as of December 31, 2005, a net gain of $2 million is expected to be reclassified to income in 2006.
        (d)The contract price under the U.K. long-term natural gas contracts is reset annually and is indexed to a basket of costs of living and energy commodity indices for the previous twelve months. The fair value of these contracts is determined by applying the difference between the contract price and the U.K. forward gas strip price to the expected sales volumes under these contracts for the next 18 months. The eighteen-month period represents approximately 90 percent of market liquidity in that region.
        (e)Certain physical commodity contracts are classified as nontraditional derivative instruments because certain volumes covered by these contracts are physically netted at particular delivery locations. Additionally, other physical contracts that involve flash title are accounted for as nontraditional derivative instruments.
        (f)The fair value of OTC interest rate swaps excludes accrued interest amounts not yet settled. As of December 31, 2005 and 2004, accrued interest approximated $3 million and $4 million. The net fair value of the OTC interest rate swaps as of December 31, 2005 and 2004 is included in long-term debt. See Note 20.

        F-30The following table sets forth quantitative information by category of derivative instrument at December 31, 2006 and 2005. These amounts are reported on a gross basis by individual derivative instrument.

         
          
         2006
         2005
         
        (In millions)

         December 31
         Assets(a)
         (Liabilities)(a)
         Assets(a)
         (Liabilities)(a)
         

         
        Commodity Instruments               
         Fair value hedges (b):               
          Exchange traded commodity futures   $–   $(4)$2 $(2)
          Over-the-counter ("OTC") commodity swaps    20  (15) 66  (2)
         Non-hedge designation:               
          Exchange-traded commodity futures   $301 $(258)$281 $(288)
          Exchange-traded commodity options    88  (93) 70  (65)
          OTC commodity swaps    44  (34) 105  (99)
          OTC commodity options    2  (1) 3  (6)
        Nontraditional Instruments               
         Long-term United Kingdom natural gas contracts (c)   $–   $(60)$–   $(513)
         Physical commodity contracts (d)    46  (64) 71  (62)
        Financial Instruments               
         Fair value hedges:               
          OTC interest rate swaps (e)   $–   $(22)$–   $(30)
         Cash flow hedges(f):               
          OTC foreign currency forwards    3  –    –    (2)

         
        (a)
        The fair value and carrying value of a derivative instrument are the same. The fair values for OTC commodity positions are determined using option-pricing models or dealer quotes. The fair values of exchange-traded commodity positions are based on market quotes derived from major exchanges. The fair values of interest rate and foreign currency swaps are based on dealer quotes. Marathon's consolidated balance sheet is reported on a net basis by brokerage firm, as permitted by master netting agreements.
        (b)
        There was no ineffectiveness associated with fair value hedges for 2006 or 2005 because the hedging instruments and the existing firm commitment contracts are priced on the same underlying index. Derivative instruments used in the fair value hedges mature between 2007 and 2008.
        (c)
        The contract price under the long-term U.K. natural gas contracts is reset annually and is indexed to a basket of costs of living and energy commodity indices for the previous twelve months. The fair value of these contracts is determined by applying the difference between the contract price and the U.K. forward gas strip price to the expected sales volumes under these contracts for the next 18 months. The 18-month period represents approximately 90 percent of market liquidity in that region.
        (d)
        Certain physical commodity contracts are classified as nontraditional derivative instruments because certain volumes covered by these contracts are physically netted at particular delivery locations. Additionally, other physical contracts that management has chosen not to designate as normal purchases or normal sales, which can include contracts that involve flash title, are accounted for as nontraditional derivative instruments.
        (e)
        The fair value of OTC interest rate swaps excludes accrued interest amounts not yet settled. As of December 31, 2006 and 2005, accrued interest approximated $4 million and $3 million. The net fair value of the OTC interest rate swaps as of December 31, 2006 and 2005 is included in long-term debt. See Note 21.
        (f)
        The ineffective portion of the changes in fair value of cash flow hedges was $3 million during 2006 and less than $1 million during 2005 on a pretax basis. Of the unrealized gains and losses recorded in accumulated other comprehensive loss as of December 31, 2006, a net gain of $2 million is expected to be reclassified to net income in 2007.

        F-28



        18.19. Fair Value of Financial Instruments
        Fair value of the financial instruments disclosed herein is not necessarily representative of the amount that could be realized or settled, nor does the fair value amount consider the tax consequences of realization or settlement. The following table summarizes financial instruments, excluding derivative financial instruments disclosed in Note 17, by individual balance sheet line item. Marathon’s financial instruments at December 31, 2005 and 2004 were:
                           
          2005 2004
             
          Fair Carrying Fair Carrying
        (In millions) December 31 Value Amount Value Amount
         
        Financial assets:
                        
         Cash and cash equivalents $2,617  $2,617  $3,369  $3,369 
         Receivables  3,514   3,514   3,220   3,220 
         Receivables from United States Steel  540   552   590   602 
         Investments and long-term receivables  268   195   266   188 
                     
          Total financial assets $6,939  $6,878  $7,445  $7,379 
         
        Financial liabilities:
                        
         Accounts payable $5,435  $5,435  $4,474  $4,474 
         Consideration payable under Libya re-entry agreement  732   732   –    –  
         Payables to United States Steel  6   6   5   5 
         Accrued interest  96   96   92   92 
         Long-term debt due within one year  315   315   16   16 
         Long-term debt  4,039   3,560   4,464   3,909 
                     
          Total financial liabilities $10,623  $10,144  $9,051  $8,496 
         
             Fair value of financial instruments classified as current assets or liabilities approximates carrying value due to the short-term maturity of the instruments. Fair value of investments and long-term receivables was based on discounted cash flows or other specific instrument analysis. Fair value of long-term debt instruments was based on market prices where available or current borrowing rates available for financings with similar terms and maturities. Fair value of the receivables from United States Steel was estimated using market prices for United States Steel debt assuming the industrial revenue bonds are redeemed on or before the tenth anniversary of the Separation per the Financial Matters Agreement.

        The fair value of the financial instruments disclosed herein is not necessarily representative of the amount that could be realized or settled, nor does the fair value amount consider the tax consequences of realization or settlement. The following table summarizes financial instruments, excluding derivative financial instruments disclosed in Note 18, by individual balance sheet line item. Marathon's financial instruments at December 31, 2006 and 2005 were:

         
          
         2006
         2005
        (In millions)

         December 31
         Fair
        Value

         Carrying
        Amount

         Fair
        Value

         Carrying
        Amount


        Financial assets:              
         Cash and cash equivalents   $2,585 $2,585 $2,617 $2,617
         Receivables    4,177  4,177  3,514  3,514
         Receivables from United States Steel    522  530  540  552
         Investments and long-term receivables(a)    461  348  268  195
            
         
         
         
          Total financial assets   $7,745 $7,640 $6,939 $6,878

        Financial liabilities:              
         Accounts payable   $5,850 $5,850 $5,435 $5,435
         Consideration payable under Libya re-entry agreement    –    –    732  732
         Payables to United States Steel    20  20  6  6
         Accrued interest    89  89  96  96
         Long-term debt due within one year(b)    450  450  302  302
         Long-term debt(b)    3,279  2,947  4,052  3,573
            
         
         
         
         Total financial liabilities   $9,688 $9,356 $10,623 $10,144

        (a)
        Excludes equity method investments and derivatives.
        (b)
        Excludes capital leases.

                The fair value of financial instruments classified as current assets or liabilities approximates carrying value due to the short-term maturity of the instruments. The fair value of investments and long-term receivables was based on discounted cash flows or other specific instrument analysis. The fair value of long-term debt instruments was based on market prices where available or current borrowing rates available for financings with similar terms and maturities. The fair value of the receivables from United States Steel was estimated using market prices for United States Steel debt assuming the industrial revenue bonds are redeemed on or before the tenth anniversary of the Separation per the Financial Matters Agreement.


        19.20. Short-Term Debt

        Marathon has a commercial paper program that is supported by the unused and available credit on the Marathon five-year revolving credit facility discussed in Note 20. At December 31, 2005, there were no commercial paper borrowings outstanding.
             Additionally, as part of the Acquisition on June 30, 2005 discussed in Note 5, Marathon assumed $1.920 billion in debt which was repaid on July 1, 2005.

        F-31Marathon has a commercial paper program that is supported by the unused and available credit on the Marathon five-year revolving credit facility discussed in Note 21. At December 31, 2006, there were no commercial paper borrowings outstanding.

                Additionally, as part of the Acquisition on June 30, 2005 discussed in Note 6, Marathon assumed $1.920 billion in debt which was repaid on July 1, 2005.

        F-29



        20.21. Long-Term Debt

                   
        (In millions)December 31 2005 2004
         
        Marathon Oil Corporation:        
         
        Revolving credit facility due 2009(a)
         $–   $–  
         6.650% notes due 2006  300   300 
         
        5.375% notes due 2007(b)
          450   450 
         6.850% notes due 2008  400   400 
         
        6.125% notes due 2012(b)
          450   450 
         
        6.000% notes due 2012(b)
          400   400 
         
        6.800% notes due 2032(b)
          550   550 
         9.375% debentures due 2012  163   163 
         9.125% debentures due 2013  271   271 
         9.375% debentures due 2022  81   81 
         8.500% debentures due 2023  123   123 
         8.125% debentures due 2023  229   229 
         
        6.570% promissory note due 2006(b)
          2   9 
         Series A medium term notes due 2022  3   3 
         
        4.750% – 6.875% obligations relating to industrial development and environmental improvement bonds and notes due 2009 – 2033(c)
          453   496 
         
        Sale-leaseback financing due 2006 – 2012(d)
          66   71 
         
        Capital lease obligation due 2012(e)
          49   51 
        Consolidated subsidiaries:        
         
        Revolving credit facility due 2009(a)
          –    –  
         Capital lease obligations due 2006 – 2020  61   44 
               
          
        Total(f)(g)
          4,051   4,091 
        Unamortized discount  (8)  (8)
        Fair value adjustments on notes subject to hedging(h)
          (30)  (10)
        Amounts due within one year  (315)  (16)
               
          Long-term debt due after one year $3,698  $4,057 
         
        (a)Marathon has a $1.5 billion five-year revolving credit agreement and MPC has a $500 million five-year revolving credit facility, both of which terminate in May 2009. These facilities each require a representation at an initial borrowing that there has been no change in the respective borrower’s consolidated financial position or operations, considered as a whole, that would materially and adversely affect such borrower’s ability to perform its obligations under its revolving credit facility. Interest on these facilities is based on defined short-term market rates. During the term of the agreements, Marathon is obligated to pay a variable facility fee on total commitments, which at December 31, 2005 was 0.125%. At December 31, 2005, there were no borrowings against these facilities.
        (b)These notes contain a make-whole provision allowing Marathon the right to repay the debt at a premium to market price.
        (c)United States Steel has assumed responsibility for repayment of $428 million of these obligations.
        (d)This sale-leaseback financing arrangement relates to a lease of a slab caster at United States Steel’s Fairfield Works facility in Alabama with a term through 2012. Marathon is the primary obligor under this lease. Under the Financial Matters Agreement, United States Steel has assumed responsibility for all obligations under this lease. This lease is an amortizing financing with a final maturity of 2012, subject to additional extensions.
        (e)This obligation relates to a lease of equipment at United States Steel’s Clairton Works cokemaking facility in Pennsylvania with a term through 2012. Marathon is the primary obligor under this lease. Under the Financial Matters Agreement, United States Steel has assumed responsibility for all obligations under this lease. This lease is an amortizing financing with a final maturity of 2012.
        (f)Required payments of long-term debt for the years 2007-2010 are $317 million, $474 million, $417 million and $19 million, respectively. Of these amounts, payments assumed by United States Steel are $16 million, $24 million, $17 million and $19 million, respectively.
        (g)In the event of a change in control of Marathon, as defined in the related agreements, debt obligations totaling $1.573 billion at December 31, 2005, may be declared immediately due and payable.
        (h)See Note 17 for information on interest rate swaps.

        (In millions)

         December 31
         2006
         2005
         

         
        Marathon Oil Corporation:         
         Revolving credit facility due 2011(a)   $–   $–   
         6.650% notes due 2006    –    300 
         5.375% notes due 2007(b)    450  450 
         6.850% notes due 2008    400  400 
         6.125% notes due 2012(b)    450  450 
         6.000% notes due 2012(b)    400  400 
         6.800% notes due 2032(b)    550  550 
         9.375% debentures due 2012(c)    123  163 
         9.125% debentures due 2013(c)    212  271 
         9.375% debentures due 2022(c)    67  81 
         8.500% debentures due 2023(c)    122  123 
         8.125% debentures due 2023(c)    181  229 
         6.570% promissory note due 2006(b)    –    2 
         Series A medium term notes due 2022    3  3 
         4.750% – 6.875% obligations relating to industrial development and environmental improvement bonds and notes due 2009 – 2033(d)    439  453 
         Sale-leaseback financing due 2007 – 2012(e)    60  66 
         Capital lease obligation due 2007 – 2012(f)    44  49 
        Consolidated subsidiaries:         
         Revolving credit facility due 2009(g)    –    –   
         Capital lease obligations due 2007 – 2020    59  61 
            
         
         
          Total(h)(i)    3,560  4,051 
        Unamortized discount    (6) (8)
        Fair value adjustments on notes subject to hedging(j)    (22) (30)
        Amounts due within one year    (471) (315)
            
         
         
          Long-term debt due after one year   $3,061 $3,698 

         
        (a)
        In May 2006, Marathon entered into an amendment of its $1.5 billion five-year revolving credit agreement, expanding the size of the facility to $2 billion and extending the termination date from May 2009 to May 2011. The facility requires a representation at an initial borrowing that there has been no change in Marathon's consolidated financial position or operations, considered as a whole, that would materially and adversely affect its ability to perform its obligations under the revolving credit facility. Interest on the facility is based on defined short-term market rates. During the term of the agreement, Marathon is obligated to pay a variable facility fee on the total commitment, which at December 31, 2006 was 0.08 percent. At December 31, 2006, there were no borrowings outstanding under this facility.
        (b)
        These notes contain a make-whole provision allowing Marathon the right to repay the debt at a premium to market price.
        (c)
        During 2006, Marathon extinguished portions of this debt. Debt with a total face value of $162 million was repurchased at a weighted average price equal to 122 percent of face value. The total premium of $35 million is reflected as loss on early extinguishment of debt in the consolidated statement of income for 2006.
        (d)
        United States Steel has assumed responsibility for repayment of $415 million of these obligations. The Financial Matters Agreement provides that, on or before the tenth anniversary of the Separation, United States Steel will provide for Marathon's dischage from any remaining liability under any of the assumed industrial revenue bonds.
        (e)
        This sale-leaseback financing arrangement relates to a lease of a slab caster at United States Steel's Fairfield Works facility in Alabama. Marathon is the primary obligor under this lease. Under the Financial Matters Agreement, United States Steel has assumed responsibility for all obligations under this lease. This lease is an amortizing financing with a final maturity of 2012, subject to additional extensions.
        (f)
        This obligation relates to a lease of equipment at United States Steel's Clairton Works cokemaking facility in Pennsylvania. Marathon is the primary obligor under this lease. Under the Financial Matters Agreement, United States Steel has assumed responsibility for all obligations under this lease. This lease is an amortizing financing with a final maturity of 2012.
        (g)
        MPC's $500 million five-year revolving credit agreement was terminated concurrent with the May 2006 amendment of Marathon's revolving credit facility.
        (h)
        Required payments of long-term debt for the years 2008-2011 are $417 million, $19 million, $21 million and $164 million. Of these amounts, payments assumed by United States Steel are $14 million, $15 million, $17 million and $161 million.
        (i)
        In the event of a change in control of Marathon, as defined in the related agreements, debt obligations totaling $1.183 billion at December 31, 2006, may be declared immediately due and payable.
        (j)
        See Note 18 for information on interest rate swaps.

                In 2006, Marathon entered into a loan agreement which provides for borrowings of up to $525 million from the Norwegian export credit agency based upon the amount of qualifying purchases by Marathon of goods and services from Norwegian suppliers. The loan agreement allows Marathon to select either a fixed or LIBOR-based floating interest rate at the time of the initial drawdown and a five-year or eight and one half-year repayment term. If Marathon elects to borrow under this agreement, the initial drawdown must occur in June 2007 with one subsequent drawdown allowed in December 2007.

        F-30



        21.22. MPC Receivables Purchase and Sale Facility

        On July 1, 2005, MPC entered into a $200 million, three-year Receivables Purchase and Sale Agreement with certain purchasers. The program was structured to allow MPC to periodically sell a participating interest in pools of eligible accounts receivable. If any receivables were sold under the facility, MPC would not guarantee the transferred receivables and would have no obligations upon default. During the term of the agreement MPC was obligated to pay a facility fee of 0.12%. Subsequent to December 31, 2005, the facility was terminated. No receivables were sold under the agreement during its term.

        F-32On July 1, 2005, MPC entered into a $200 million, three-year Receivables Purchase and Sale Agreement with certain purchasers. The program was structured to allow MPC to periodically sell a participating interest in pools of eligible accounts receivable. During 2006, the facility was terminated. No receivables were sold under the agreement during its term.



        22.23. Supplemental Cash Flow Information
                         
        (In millions) 2005 2004 2003
         
        Net cash provided from operating activities from continuing operations included:
                    
         Interest and other financing costs paid (net of amounts capitalized) $174  $206  $254 
         Income taxes paid to taxing authorities  1,544   674   537 
         Income tax settlements paid to United States Steel  6   3   16 
         
        Commercial paper and revolving credit arrangements – net:
                    
         Commercial paper – issued $3,896  $–   $4,733 
           – repayments  (3,896)  –    (4,833)
         Credit agreements – borrowings  10   –    3 
           – repayments  (10)  –    (34)
         Ashland credit agreements – borrowings  –    653   182 
            – repayments  –    (653)  (182)
                  
           Total $–   $  $(131)
         
        Noncash investing and financing activities:
                    
         Asset retirement costs capitalized $171  $66  $61 
         Debt payments assumed by United States Steel  44   13   5 
         Capital lease obligations:            
          Assets acquired  18   –    41 
          Assumed by United States Steel  8   –    59 
         Net assets contributed to joint ventures  7   3   42 
         Acquisitions:            
          Debt and other liabilities assumed  5,414   –    110 
          Common stock issued to seller  955   –    –  
          Receivables transferred to seller  911   –    –  
         Disposal of assets:            
          Asset retirement obligations assumed by buyer  6   –    15 
         Joint venture dissolution  –    –    212 
         Liabilities assumed by buyer of discontinued operations  –    –    212 
         

        (In millions)

         2006
         2005
         2004
         

         
        Net cash provided from operating activities from continuing operations included:          
         Interest paid (net of amounts capitalized) $96 $174 $206 
         Income taxes paid to taxing authorities  4,149  1,528  672 
         Income tax settlements paid to United States Steel  35  6  3 

         
        Commercial paper and revolving credit arrangements, net:          
         Commercial paper – issuances $1,321 $3,896 $–   
                                          – repayments  (1,321) (3,896) –   
         Credit agreements – borrowings  –    10  –   
                                          – repayments  –    (10) –   
         Ashland credit agreements – borrowings  –    –    653 
                                                          – repayments  –    –    (653)
          
         
         
         
          Total $–   $–   $–   

         
        Noncash investing and financing activities:          
         Asset retirement costs capitalized $286 $171 $66 
         Debt payments assumed by United States Steel  24  44  13 
         Capital lease obligations:          
          Assets acquired  1  18  –   
         Net assets contributed to joint ventures  –    7  3 
         Acquisitions:          
          Debt and other liabilities assumed  26  4,161  –   
          Common stock issued to seller  –    955  –   
          Receivables transferred to seller  –    911  –   
         Disposal of assets:          
          Asset retirement obligations assumed by buyer  9  6  –   

         

        F-33



        23. Pensions24. Defined Benefit and Other Postretirement Plans

        Marathon has noncontributory defined benefit pension plans covering substantially all domestic employees as well as international employees located in Ireland, Norway and the United Kingdom. Benefits

        under these plans are based primarily on years of service and final average pensionable earnings. Marathon adopted SFAS No. 158, which applies to such plans, prospectively as of December 31, 2006.

                Marathon also has defined benefit plans for other postretirement benefits covering most employees. Health care benefits are provided through comprehensive hospital, surgical and major medical benefit provisions subject to various cost sharing features. Life insurance benefits are provided to certain nonunion and union-represented retiree beneficiaries. Other postretirement benefits have not been funded in advance.

        F-31


        Obligations and Funded Statusfunded status

        The following summarizes the obligations and funded status for Marathon’s pension and other postretirement benefit plans:
                                 
          Pension Benefits Other Benefits
             
          2005 2004 2005 2004
                 
        (In millions) U.S. Int’l U.S. Int’l    
         
        Change in benefit obligations
                                
        Benefit obligations at January 1 $1,750  $322  $1,591  $262  $697  $733 
        Service cost  109   11   94   9   20   18 
        Interest cost  104   16   95   14   38   42 
        Actuarial (gain) loss  187(a)  (6)  160   41   40(a)  (65)(b)
        Plan amendment  –    –    –    –    10   –  
        Net settlements and curtailments  –    –    (84)  –    –    (1)
        Mergers and acquisitions(c)
          2   –    –    –    2   –  
        Benefits paid  (97)  (5)  (106)  (4)  (31)  (30)
                           
        Benefit obligations at December 31 $2,055  $338  $1,750  $322  $776  $697 
         
        Change in plan assets
                                
        Fair value of plan assets at January 1 $949  $185  $936  $139         
        Actual return on plan assets  45   16   79   27         
        Employer contribution  128   26   121   24         
        Settlement payments  –    –    (81)  –          
        Benefits paid from plan assets  (97)  (5)  (106)  (5)        
                           
        Fair value of plan assets at December 31 $1,025  $222  $949  $185         
         
        Funded status of plans at December 31
         $(1,030) $(116) $(801) $(137) $(776) $(697)
        Unrecognized net transition asset  –    –    (4)  –    –    –  
        Unrecognized prior service costs (credits)  23   –    33   –    (64)  (91)
        Unrecognized net losses  651   106   730   127   184   183 
                           
        Accrued benefit cost $(356) $(10) $(42) $(10) $(656) $(605)
         
        Amounts recognized in the consolidated balance sheet:
                                
        Prepaid benefit cost $–   $–   $128  $–   $–   $–  
        Accrued benefit liability  (520)  (91)  (257)  (81)  (656)  (605)
        Intangible asset  16   –    20   –    –    –  
        Accumulated other comprehensive income(d)
          148   81   67   71   –    –  
                           
        Prepaid (accrued) benefit cost $(356) $(10) $(42) $(10) $(656) $(605)
         
        (a)Includes the impact of decreasing the retirement age assumption by two years and increasing the lump sum election rate assumption from 90 percent to 96 percent based on changing trends in Marathon’s experience, which increased the obligations by $109 million.
        (b)Includes the impact related to the Medicare Prescription Drug, Improvement and Modernization Act of 2003, which reduced the obligation by $93 million.
        (c)Includes the addition of certain employees of the maleic anhydride business acquired as part of the Acquisition.
        (d)Excludes the effects of minority interest as of December 31, 2004 and income taxes.
             The accumulated benefit obligation for all defined benefit pension plans was $1.748 billion and $1.423 billion at December 31, 2005 and 2004, respectively. Other Benefits in the above table is not applicable to Marathon’s foreign subsidiaries as those  –  The following summarizes the obligations and funded status for Marathon's defined benefit pension and other postretirement plans:

         
         Pension Benefits
         Other Benefits

         
         
         2006

         2005

         2006

         2005

         
        (In millions)

         U.S.
         Int'l
         U.S.
         Int'l
          
          
         

         
        Change in benefit obligations                   
         Benefit obligations at January 1 $2,055 $338 $1,750 $322 $776 $697 
          Service cost  117  17  109  11  23  20 
          Interest cost  113  17  104  16  42  38 
          Actuarial (gain) loss  (207)(a) 15  187(b) (6) 9  40(b)
          Plan amendment  117(c) –    –    –    –    10 
          Mergers and acquisitions(d)  –    –    2  –    –    2 
          Benefits paid  (118) (6) (97) (5) (29(e) (31)
          
         
         
         
         
         
         
        Benefit obligations at December 31 $2,077 $381 $2,055 $338 $821 $776 

         
        Change in plan assets                   
         Fair value of plan assets at January 1 $1,025 $222 $949 $185       
          Actual return on plan assets  175  56  45  16       
          Employer contributions  606  29  128  26       
          Benefits paid from plan assets  (118) (6) (97) (5)      
          
         
         
         
               
         Fair value of plan assets at December 31 $1,688 $301 $1,025 $222       

         
        Funded status of plans at December 31, 2006 $(389)$(80)      $(821)   
         Amounts recognized in the consolidated balance sheet:                   
          Current liabilities $(8)$(1)      $(36)   
          Noncurrent liabilities  (381) (79)       (785)   
          
         
               
            
          Accrued benefit cost $(389)$(80)      $(821)   

         
        Pretax amounts recognized in accumulated other comprehensive income in 2006(f):                   
         Net loss $338 $70       $184    
         Prior service cost (credit)  132  –          (53)   

         
        Funded status of plans at December 31, 2005       $(1,030)$(116)   $(776)
         Unrecognized prior service cost (credit)        23  –       (64)
         Unrecognized net loss        651  106     184 
                
         
            
         
         Accrued benefit cost       $(356)$(10)   $(656)

         
        Amounts recognized in the consolidated balance sheet at December 31, 2005:                   
         Accrued benefit liability       $(520)$(91)   $(656)
         Intangible asset        16  –       –   
         Accumulated other comprehensive income, excluding tax effects        148  81     –   
                
         
            
         
         Accrued benefit cost       $(356)$(10)   $(656)

         
        (a)
        Includes the impact of an increase in the discount rate to 5.80 percent from 5.50 percent and demographic assumption changes, which decreased the obligation by $112 million.
        (b)
        Includes the impact of decreasing the retirement age assumption by two years and increasing the lump sum election rate assumption from 90 percent to 96 percent based on changing trends in Marathon's experience, which increased the obligation by $109 million.
        (c)
        Includes the impact of plan design changes related to the update of the mortality table used in the plans' definition of actuarial equivalence and lump sum calculations and a 20 percent retiree cost of living adjustment for annuitants.
        (d)
        Includes the addition of certain employees of the maleic anhydride business acquired as part of the Acquisition.
        (e)
        Benefits paid include the $3 million Medicare Subsidy received.
        (f)
        Excludes amounts related to LOOP LLC, an equity method investee with defined benefit pension and postretirement plans for which a net loss of $6 million is reflected in accumulated other comprehensive income as a result of adopting SFAS No. 158 as of December 31, 2006, reflecting Marathon's 51 percent share.

                The accumulated benefit obligation for all defined benefit pension plans was $1.912 billion and $1.748 billion at December 31, 2006 and 2005. Marathon's international subsidiaries do not sponsor any defined benefit postretirement plans other than pension plans.

             The following summarizes all defined benefit pension plans that have accumulated benefit obligations in excess of plan assets:
                         
          2005 2004
             
        (In millions)December 31 U.S. Int’l U.S. Int’l
         
        Projected benefit obligations $(2,055) $(338) $(1,248) $(322)
        Accumulated benefit obligations  (1,435)  (313)  (790)  (265)
        Fair value of plan assets  1,025   222   535   185 
         
             On June 30, 2005, as a result of the Acquisition, MPC’s pension and other postretirement benefit plan obligations were remeasured using current discount rates and plan assumptions. The discount rate was decreased to 5.25 percent from 5.75 percent. As part of the application of the purchase method of accounting, MPC recognized 38 percent of its unrecognized net transition gain, prior service costs and actuarial losses related to its pension and other postretirement benefit plans. As a result, obligations related to the pension and other postretirement benefit plans increased by $264 million and $28 million.

        F-34        The following summarizes all of Marathon's defined benefit pension plans that have accumulated benefit obligations in excess of plan assets.

         
         December 31
         
         
         2006

         2005

         
        (In millions)

         U.S.
         Int'l
         U.S.
         Int'l
         

         
        Projected benefit obligations $(92)$(354)$(2,055)$(338)
        Accumulated benefit obligations  (62) (331) (1,435) (313)
        Fair value of plan assets  –    278  1,025  222 

         

        F-32


                On June 30, 2005, as a result of the Acquisition, MPC's defined benefit pension and other postretirement plan obligations were remeasured using current discount rates and plan assumptions. The discount rate was decreased to 5.25 percent from 5.75 percent. As part of the application of the purchase method of accounting, MPC recognized 38 percent of its unrecognized net transition gain, prior service costs and actuarial losses related to its defined benefit pension and other postretirement plans. As a result, obligations related to the defined benefit pension and other postretirement plans increased by $264 million and $28 million.


        Components of net periodic benefit cost and other comprehensive income  –  The following summarizes the net periodic benefit costs and the amounts recognized as other comprehensive income for Marathon's defined benefit pension and other postretirement plans.

         
          
         Pension Benefits
         Other Benefits
         
         
          
         2006

         2005

         2004

         2006

         2005

         2004

         
        (In millions)

          
         U.S.
         Int'l
         U.S.
         Int'l
         U.S.
         Int'l
          
          
          
         

         
        Components of net periodic benefit cost:                            
         Service cost $117 $17 $109 $11 $94 $9 $23 $20 $18 
         Interest cost  113  17  104  16  95  14  42  38  42 
         Expected return on plan assets  (103) (15) (83) (12) (84) (10) –    –    –   
         Amortization – net transition gain  –    –    (3) –    (4) –    –    –    –   
               – prior service cost (credit)  8  –    4  –    4  –    (11) (12) (14)
               – actuarial loss  34  7  47  8  39  7  9  7  11 
         Multi-employer and other plans  2  –    2  –    2  –    3  3  3 
         Settlement, curtailment and termination losses (gains)(a)  –    –    –    –    37  –    –    –    (9)
            
         
         
         
         
         
         
         
         
         
        Net periodic benefit cost $171 $26 $180 $23 $183 $20 $66 $56 $51 

         
        (a)
        Includes business transformation costs.

         
         Pension Benefits
         
         
         2005
         2004
         
        (In millions)

         U.S.
         Int'l
         U.S.
         Int'l
         

         
        Increase (decrease) in minimum liability included in other comprehensive income, excluding tax effects and minority interest $81 $10 $(18)$(13)

         

                The estimated net loss and prior service cost for the defined benefit pension plans that will be amortized from accumulated other comprehensive income into net periodic benefit cost in 2007 are $21 million and $13 million. The estimated net loss and prior service credit for the other defined benefit postretirement plans that will be amortized from accumulated other comprehensive income into net periodic benefit cost in 2007 are $11 million and $10 million.

        Net Periodic Benefit CostPlan assumptions
        The following summarizes the net periodic benefit costs for Marathon’s pension and other postretirement benefit plans.
                                              
          Pension Benefits Other Benefits
             
          2005 2004 2003 2005 2004 2003
                     
        (In millions) U.S. Int’l U.S. Int’l U.S. Int’l      
         
        Components of net periodic benefit cost
                                            
        Service cost $109  $11  $94  $9  $87  $7  $20  $18  $21 
        Interest cost  104   16   95   14   90   11   38   42   46 
        Expected return on plan assets  (83)  (12)  (84)  (10)  (84)  (7)  –    –    –  
        Amortization – net transition gain  (3)  –    (4)  –    (4)  –    –    –    –  
         – prior service costs (credits)  4   –    4   –    5   –    (12)  (14)  (10)
         – actuarial loss  47   8   39   7   32   5   7   11   12 
        Multi-employer and other plans  2   –    2   –    2   –    3   3   2 
        Settlement, curtailment and termination losses (gains)(a)
          –    –    37   –    6   1   –    (9)  (16)
                                    
        Net periodic benefit cost $180  $23  $183  $20  $134  $17  $56  $51  $55 
         
        (a)Includes business transformation costs.
                                             
          Pension Benefits Other Benefits
             
          2005 2004 2003 2005 2004 2003
                     
        (In millions) U.S. Int’l U.S. Int’l U.S. Int’l      
         
        Increase (decrease) in minimum liability included in other comprehensive income, excluding tax effects and minority interest $81  $10  $(18) $(13) $33  $52   N/A   N/A   N/A 
         
                    Plan Assumptions
        The following summarizes the assumptions used to determine the benefit obligations and net periodic benefit costs for Marathon’s pension and other postretirement benefit plans.
                                              
          Pension Benefits Other Benefits
             
          2005 2004 2003 2005 2004 2003
                     
          U.S. Int’l U.S. Int’l U.S. Int’l      
         
        Weighted-average assumptions used to determine benefit obligation at December 31:
                                            
         Discount rate  5.50%   4.70%   5.75%   5.30%   6.25%   5.40%   5.75%   5.75%   6.25% 
         Rate of compensation increase  4.50%   4.55%   4.50%   4.60%   4.50%   4.50%   4.50%   4.50%   4.50% 
        Weighted average actuarial assumptions used to determine net periodic benefit cost for years ended December 31:
                                            
         
        Discount rate(a)
          5.57%   5.30%   6.25%   5.40%   6.50%   5.50%   5.57%   6.25%   6.50% 
         Expected long-term return on plan assets  8.50%   6.87%   9.00%   6.87%   9.00%   7.00%   N/A   N/A   N/A 
         Rate of compensation increase  4.50%   4.60%   4.50%   4.50%   4.50%   4.25%   4.50%   4.50%   4.50% 
         
        (a)On June 30, 2005 due to the Acquisition, MPC’s discount rate was decreased to 5.25% from 5.75%.
          –  The following summarizes the assumptions used to determine the benefit obligations and net periodic benefit cost for Marathon's defined benefit pension and other postretirement plans.

         
         Pension Benefits
         Other Benefits
         
         
         2006

         2005

         2004

         2006

         2005

         2004

         
          

         U.S.
         Int'l
         U.S.
         Int'l
         U.S.
         Int'l
          
          
          
         

         
        Weighted-average assumptions used to determine benefit obligation at December 31:                   
         Discount rate 5.80%5.20%5.50%4.70%5.75%5.30%5.90%5.75%5.75%
         Rate of compensation increase 4.50%4.75%4.50%4.55%4.50%4.60%4.50%4.50%4.50%
        Weighted average actuarial assumptions used to determine net periodic benefit cost for years ended December 31:                   
          Discount rate(a) 5.70%4.70%5.57%5.30%6.25%5.40%5.75%5.57%6.25%
          Expected long-term return on plan assets 8.50%6.07%8.50%6.87%9.00%6.87%      
          Rate of compensation increase 4.50%4.55%4.50%4.60%4.50%4.50%4.50%4.50%4.50%

         
        (a)
        On July 31, 2006, due to an interim remeasurement, the discount rate for the U.S. pension plans was increased to 6.00 percent from 5.50 percent. Also, on June 30, 2005 due to the Acquisition, the discount rate for the MPC pension plan was decreased to 5.25 percent from 5.75 percent.

        F-33


          Expected Long-Term Returnlong-term return on Plan Assets

        plan assets

        U.S. Plans –

        Historical markets are studied and long-term historical relationships between equities and fixed income are preserved consistent with the widely accepted capital market principle that assets with higher volatility generate a greater return over the long term. Certain components of the asset mix are modeled with various assumptions regarding inflation, debt returns and stock yields. Our assumptions are compared to those of peer companies and historical returns for reasonableness and appropriateness.
        Historical markets are studied and long-term historical relationships between equities and fixed income securities are preserved consistent with the widely accepted capital market principle that assets with higher volatility generate a greater return over the long term. Certain components of the asset mix are modeled with various assumptions regarding inflation, debt returns and stock yields. The assumptions are compared to those of peer companies and to historical returns for reasonableness and appropriateness.

        International Plans –

        The overall expected long-term return on plan assets is derived using the expected returns on the individual asset classes, weighted by holdings as of year end. The long-term rate of return on equity investments is assumed to be
        The overall expected long-term return on plan assets is derived using the expected returns on the individual asset classes, weighted by holdings as of year end. The long-term rate of return on equity investments is assumed to be 2.5 percent greater than the yield on local government bonds. Expected returns on debt securities are estimated directly at market yields and on cash are estimated at the local currency base rate.

        F-35


        2.5 percent greater than the yield on local government bonds. Expected returns on debt securities are taken directly at market yields and cash is taken at the local currency base rate.

        Assumed Health Care Cost Trend
        The following summarizes the assumed health care cost trend rates:
                     
        December 31 2005 2004 2003
         
        Health care cost trend rate assumed for next year  8.5%  9.0%  9.5%
        Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)  5.0%  5.0%  5.0%
        Year that the rate reaches the ultimate trend rate  2012   2012   2012 
         
             Assumed health care cost trend rates have a significant effect on the amounts reported for retiree health care plans. A one-percentage-point change in assumed health care cost trend rates would have the following effects:
                 
          1-Percentage- 1-Percentage-
        (In millions) Point Increase Point Decrease
         
        Effect on total of service and interest cost components $11  $(9)
        Effect on other postretirement benefit obligations  120   (102)
         
        health care cost trend –The following summarizes the assumed health care cost trend rates.

         
         December 31
         2006
         2005
         2004
         

         
        Health care cost trend rate assumed for the following year         
         Medical   8.0%8.5%9.0%
         Prescription Drugs(a)   11.0%8.5%9.0%
        Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)         
         Medical   5.0%5.0%5.0%
         Prescription Drugs(a)   6.0%5.0%5.0%
        Year that the rate reaches the ultimate trend rate         
         Medical   2012 2012 2012 
         Prescription Drugs(a)   2016 2012 2012 

         
        (a)
        Prior to 2006, the assumed cost trend rate and the year that it would reach the ultimate trend rate for prescription drugs were the same as those for other medical costs.

                Assumed health care cost trend rates have a significant effect on the amounts reported for defined benefit retiree health care plans. A one-percentage-point change in assumed health care cost trend rates would have the following effects:

        (In millions)

         1-Percentage-
        Point Increase

         1-Percentage-
        Point Decrease

         

         
        Effect on total of service and interest cost components $11 $(9)
        Effect on other postretirement benefit obligations  114  (93)

         

        Plan Assetsassets

        The following summarizes the pension plans’ weighted-average asset allocations by asset category:
                          
          2005 2004
             
          U.S. Int’l U.S. Int’l
         
        Equity securities  76%  74%  78%  73%
        Debt securities  22%  24%  21%  24%
        Real estate  2%  –    1%  –  
        Other  –    2%  –    3%
                     
         Total  100%  100%  100%  100%
         
          –  The following summarizes the defined benefit pension plans' weighted-average asset allocations by asset category.

         
         2006
         2005
         
         
         U.S.
         Int'l
         U.S.
         Int'l
         

         
        Equity securities 79%73%76%74%
        Debt securities 19%26%22%24%
        Real estate 2%–   2%–   
        Other –   1%–   2%
          
         
         
         
         
         Total 100%100%100%100%

         

          Plan Investment Policiesinvestment policies and Strategiesstrategies

        U.S. Plans –

        The investment policy reflects the funded status of the plans and Marathon’s future ability to make further contributions. Historical performance and future expectations suggest that common stocks will provide higher total investment returns than fixed-income securities over a long-term investment horizon. As a result, equity investments will likely continue to exceed 50 percent of the value of the fund. Accordingly, bond and other fixed income investments will comprise the remainder of the fund. Short-term investments shall reflect the liquidity requirements for making pension payments. The plans’ targeted asset allocation is comprised of 75 percent equities and 25 percent debt securities. Management of the plans’ assets is delegated to the United States Steel and Carnegie Pension Fund. The fund manager has discretion to move away from the target allocations based upon the manager’s judgment as to current confidence or concern for the capital markets. Investments are diversified by industry and type, limited by grade and maturity. The policy prohibits investments in any securities in the steel industry and allows derivatives subject to strict guidelines. Investment performance and risk is measured and monitored on an ongoing basis through quarterly investment meetings and periodic asset and liability studies.
        The investment policy reflects the funded status of the plans and Marathon's future ability to make further contributions. Historical performance and future expectations suggest that common stocks will provide higher total investment returns than fixed-income securities over a long-term investment horizon. As a result, equity investments will likely continue to exceed 50 percent of the value of the fund. Accordingly, bond and other fixed-income investments will comprise the remainder of the fund. Short-term investments shall reflect the liquidity requirements for making pension payments. The plans' targeted asset allocation is comprised of 75 percent equity securities and 25 percent fixed-income and real estate-related securities. Management of the plans' assets is delegated to the United States Steel and Carnegie Pension Fund. The fund manager has limited discretion to move away from the target allocations based upon the manager's judgment as to current confidence or concern for the capital markets. Investments are diversified by industry and type, limited by grade and maturity. The policy prohibits investments in any securities in the steel industry and allows derivatives subject to strict guidelines, such that derivatives may only be written against equity securities in the portfolio. Investment performance and risk is measured and monitored on an ongoing basis through quarterly investment meetings and periodic asset and liability studies.

        International Plans –

        The objective of the investment policy is to achieve a long-term return which is consistent with assumptions made by the actuary in determining the funding requirements of the plans. The target asset allocation of approximately 75 percent equities and 25 percent debt securities and the unitized pool approach meets this objective and controls the various risks to which the plans’ assets are exposed, including matching the timing of estimated future obligations to the maturities of the plans’ assets. The day-to-day management of the plans’ assets is delegated to several professional investment managers. The spread of assets by type and the investment managers’ policies on investing in individual securities within each type provide adequate diversification of investments. The use of derivatives by the investment managers is permitted and plan specific, subject to strict guidelines. Investment performance and risk is measured and monitored on an ongoing basis through quarterly investment portfolio reviews and periodic asset and liability studies.
        The objective of the investment policy is to achieve a long-term return which is consistent with assumptions made by the actuary in determining the funding requirements of the plans. The target asset allocation is approximately 75 percent equity securities and 25 percent debt securities. The day-to-day management of

        F-36F-34


        the plans' assets is delegated to several professional investment managers. The spread of assets by type and the investment managers' policies on investing in individual securities within each type provide adequate diversification of investments. The use of derivatives by the investment managers is permitted and plan specific, subject to strict guidelines. Investment performance and risk is measured and monitored on an ongoing basis through quarterly investment portfolio reviews and periodic asset and liability studies.

          Cash flows

        Plan Contributions –Marathon expects to make contributions to the Company's funded pension plans of approximately $50 million in 2007. Cash contributions to be paid from the general assets of the Company for the unfunded pension and postretirement benefit plans are expected to be approximately $8 million and $41 million in 2007.


                    Cash Flows
                    Contributions
        Marathon expects to make contributions to their funded pension plans in 2006 of between $155 million and $345 million. Cash contributions to be paid from the general assets of the Company for both the unfunded pension and postretirement benefit plans are expected to be approximately $3 million and $39 million in 2006.
        Estimated Future Benefit Payments –
        The following gross benefit payments, which reflect expected future service, as appropriate, are expected to be paid:
                     
          Pension Other
          Benefits Benefits(a)
             
        (In millions) U.S. Int’l  
         
        2006 $122  $5  $39 
        2007  136   6   41 
        2008  153   7   43 
        2009  171   8   47 
        2010  186   9   50 
        2011 through 2015  1,144   65   293 
         
        (a)Expected Medicare reimbursements for 2006 through 2015 total $50 million.
             Marathon also contributes to several defined contribution plans for eligible employees. Contributions to these plans totaled $39 million in 2005, $35 million in 2004 and $37 million in 2003.
        The following gross benefit payments, which reflect expected future service, as appropriate, are expected to be paid in the years indicated:

         
         Pension Benefits
         Other
        Benefits(a)

        (In millions)

         U.S.
         Int'l
          

        2007 $151 $6 $41
        2008  166  7  44
        2009  182  8  48
        2010  195  9  52
        2011  208  11  56
        2012 through 2016  1,235  75  329

        (a)
        Expected Medicare reimbursements for 2007 through 2016 total $64 million.

        Other Plan Contributions – Marathon also contributes to several defined contribution plans for eligible employees. Contributions to these plans totaled $47 million in 2006, $39 million in 2005 and $35 million in 2004.


        24.25. Asset Retirement Obligations

        Changes in asset retirement obligations during the year were:
                  
        (In millions) 2005 2004
         
        Asset retirement obligations as of January 1 $477  $390 
         Liabilities incurred  20   17 
         Liabilities settled  (9)  (3)
         Accretion expense (included in depreciation, depletion and amortization)  29   24 
         Adoption of FIN No. 47  53   –  
         Revisions of previous estimates  141   49 
               
        Asset retirement obligations as of December 31 $711  $477 

                The following summarizes the changes in asset retirement obligations:

        (In millions)

         2006
         2005
         

         
        Asset retirement obligations as of January 1 $711 $477 
         Liabilities incurred  29  20 
         Liabilities settled  (16) (9)
         Accretion expense (included in depreciation, depletion and amortization)  43  29 
         Adoption of FIN No. 47  –    53 
         Revisions of previous estimates  277  141 
          
         
         
        Asset retirement obligations as of December 31 $1,044 $711 

         


        25.26. Stock-Based Compensation Plans

        The following is a summary of stock option and SARs activity:
                  
          Shares Price(a)
         
        Balance December 31, 2002  8,064,610  28.70 
         Granted  1,729,800   25.58 
         Exercised  (642,265)  24.48 
         Canceled  (145,765)  30.27 
               
        Balance December 31, 2003  9,006,380   28.33 
         Granted  2,067,300   33.28 
         Exercised  (2,963,546)  17.17 
         Canceled  (96,886)  30.78 
             �� 
        Balance December 31, 2004  8,013,248   29.84 
         Granted  1,894,720   50.28 
         Exercised  (3,786,828)  29.37 
         Canceled  (161,486)  34.96 
               
        Balance December 31, 2005(b)
          5,959,654   36.50 
         
        (a)Weighted-average exercise price.
        (b)Of the options outstanding as of December 31, 2005, 4,851,892 and 1,107,762 were outstanding under the 2003 Incentive Compensation Plan and 1990 Stock Plan.

        F-37Description of the plans –The Marathon Oil Corporation 2003 Incentive Compensation Plan (the "Plan") authorizes the Compensation Committee of the Board of Directors to grant stock options, stock appreciation rights, stock awards, cash awards and performance awards to employees. The Plan also allows Marathon to provide equity compensation to its non-employee directors. No more than 20,000,000 shares of common stock may be issued under the Plan, and no more than 8,500,000 of those shares may be used for awards other than stock options or stock appreciation rights. Shares subject to awards that are forfeited, terminated, settled in cash, exchanged for other awards, tendered to satisfy the purchase price of an award or withheld to satisfy tax obligations or that expire unexercised or otherwise lapse become available for future grants. Shares issued as a result of awards granted under the Plan are generally funded out of common stock held in treasury, except to the extent there are insufficient treasury shares, in which case new common shares are issued.

                The Plan replaced the 1990 Stock Plan, the Non-Officer Restricted Stock Plan, the Non-Employee Director Stock Plan, the deferred stock benefit provision of the Deferred Compensation Plan for Non-Employee Directors, the Senior Executive Officer Annual Incentive Compensation Plan and the Annual Incentive Compensation Plan (the "Prior Plans"). No new grants will be made from the Prior Plans. Any awards previously granted under the Prior Plans shall continue to vest and/or be exercisable in accordance with their original terms and conditions.

          Stock-based awards under the Plan

        Stock options – Marathon grants stock options under the Plan. Marathon's stock options represent the right to purchase shares of common stock at the fair market value of the common stock on the date of grant. Through 2004, certain options were granted with a tandem stock appreciation right, which allows the recipient to instead elect to receive cash and/or common stock equal to the excess of the fair market value of shares of common stock, as determined in accordance with the Plan, over the option price of the shares. Most stock options granted under the Plan vest ratably over a three-year period and have a maximum term of ten years from the date they are granted.

        F-35


        Stock appreciation rights – Prior to 2005, Marathon granted SARs under the Plan. Similar to stock options, stock appreciation rights represent the right to receive a payment equal to the excess of the fair market value of shares of common stock on the date the right is exercised over the grant price. Certain SARs were granted as stock-settled SARs and others were granted in tandem with stock options. In general, SARs that have been granted under the Plan vest ratably over a three-year period and have a maximum term of ten years from the date they are granted.

        Stock-based performance awards – In 2003 and 2004, the Compensation Committee granted stock-based performance awards to certain officers of Marathon and its consolidated subsidiaries under the Plan. Beginning in 2005, Marathon discontinued granting stock-based performance awards and instead grants cash-settled performance units to officers. The stock-based performance awards represent shares of common stock that are subject to forfeiture provisions and restrictions on transfer. Those restrictions may be removed if certain pre-established performance measures are met. The stock-based performance awards granted under the Plan will vest at the end of a 36-month performance period to the extent that the performance targets are achieved and the recipient is employed by Marathon on that date. Additional shares could be granted at the end of this performance period should performance exceed the targets. Prior to vesting, the recipients have the right to vote and receive dividends on the target number of shares awarded. However, the shares are not transferable until after they vest.

        Restricted stock –Marathon grants restricted stock and restricted stock units under the Plan. In 2005, the Compensation Committee began granting time-based restricted stock to officers as part of their annual long-term incentive package. The restricted stock awards to officers vest three years from the date of grant, contingent on the recipient's continued employment. Marathon also grants restricted stock to certain non-officer employees and restricted stock units to certain international non-officer employees (together with the restricted stock granted to officers above, "restricted stock awards") based on their performance within certain guidelines and for retention purposes. The restricted stock awards to non-officers generally vest in one-third increments over a three-year period, contingent on the recipient's continued employment. Prior to vesting, all restricted stock recipients have the right to vote such stock and receive dividends thereon. The non-vested shares are not transferable and are held by the Company's transfer agent.

        Common stock units –Marathon maintains an equity compensation program for its non-employee directors under the Plan. All non-employee directors other than the Chairman receive annual grants of common stock units under the Plan and they are required to hold those units until they leave the Board of Directors. When dividends are paid on Marathon common stock, directors receive dividend equivalents in the form of additional common stock units. Prior to January 1, 2006, non-employee directors had the opportunity to receive a matching grant of up to 1,000 shares of common stock if they purchased an equivalent number of shares within 60 days of joining the Board.

        Stock-based compensation expense  –  Total employee stock-based compensation expense was $83 million, $111 million and $61 million in 2006, 2005 and 2004. The total related income tax benefits were $31 million, $39 million and $22 million. In 2006, cash received upon exercise of stock option awards was $50 million. Tax benefits realized for deductions during 2006 that were in excess of the stock-based compensation expense recorded for options exercised and other stock-based awards vested during the period totaled $36 million. Cash settlements of stock option awards totaled $3 million in 2006.

        Stock option awards granted  –  During 2006, 2005 and 2004, Marathon granted stock option awards to both officer and non-officer employees. The weighted average grant date fair values of these awards were based on the following Black-Scholes assumptions:

         
         2006
         2005
         2004
         

         
        Weighted average exercise price per share $75.68 $50.28 $33.61 
        Expected annual dividends per share $1.60 $1.32 $1.00 
        Expected life in years  5.1  5.5  5.5 
        Expected volatility  28% 28% 32%
        Risk-free interest rate  5.0% 3.8% 3.9%
          
         
         
         
        Weighted average grant date fair value of stock option awards granted $20.37 $12.30 $8.83 

         

        F-36


        The following table presents information on stock options and SARs at December 31, 2005:
                              
          Outstanding Exercisable
             
          Number   Number  
        Range of of Shares Weighted-Average   of Shares  
        Exercise Under Remaining Weighted-Average Under Weighted-Average
        Prices Option Contractual Life Exercise Price Option Exercise Price
         
        $22.38 – 25.52  1,267,428   6.6  $25.49   744,830  $25.48 
        $26.91 – 30.88  637,360   5.6   28.44   625,694   28.43 
        $32.52 – 34.00  2,190,246   7.7   33.48   897,602   33.30 
        $47.65 – 51.67  1,864,620   9.5   50.28   –    –  
                        
         Total  5,959,654   7.9   36.50   2,268,126   29.39 
         
        The following table presents information on restricted stock grants:
                      
          2005 2004 2003
         
        2003 Incentive Compensation Plan:(a)
                    
         Number of shares granted  633,420   360,070   293,710 
         Weighted-average grant-date fair value per share $54.24  $34.42  $26.01 
         
        1990 Stock Plan:(b)
                    
         Number of shares granted      99,613   39,960 
         Weighted-average grant-date fair value per share     $33.61  $25.52 
         
        (a)Of the shares granted under the 2003 Incentive Compensation Plan, 52,226 have vested and 95,656 have been cancelled or forfeited. In addition to the shares, 140,000 restricted stock units have been granted to international participants under the plan, 4,182 have vested and 1,900 have been cancelled or forfeited. Thus, as of December 31, 2005, 1,139,318 shares and 133,918 units were outstanding under the plan.
        (b)Of the shares granted under the 1990 Stock Plan, 610,016 have vested and 314,956 have been cancelled or forfeited. As of December 31, 2005, no additional shares remain outstanding under the plan.
             In 2005, 6,975,600 cash-based performance units were granted to officers under the 2003 Incentive Compensation Plan, none have vested and 144,800 have been cancelled or forfeited. Thus, as of December 31, 2005, 6,830,800 units were outstanding under the Plan. The target value of each performance unit granted is $1, with actual payout varying from zero percent to 200 percent of the target value based on a 36-month measurement period.
             On January 1, 2005 and 2004, each non-employee director was granted additional stock-based compensation valued at $60,000 and $40,000, respectively, in the form of common stock units. Common stock units are book entry units equal in value to a share of stock. During 2005, 2004 and 2003, 24,982, 21,786 and 15,799 units of stock were issued.
        26. Leases
        Marathon leases a wide variety of facilities and equipment under operating leases, including land and building space, office equipment, production facilities and transportation equipment. Most long-term leases include renewal options and, in certain leases, purchase options. Future minimum commitments for capital lease obligations (including sale-leasebacks accounted for as financings) and for operating lease obligations having remaining noncancelable lease terms in excess of one year are as follows:
                  
          Capital Operating
          Lease Lease
        (In millions) Obligations Obligations
         
        2006 $27  $111 
        2007  36   61 
        2008  27   52 
        2009  27   43 
        2010  28   35 
        Later years  96   258 
        Sublease rentals  –    (43)
               
         Total minimum lease payments  241  $517 
        Less imputed interest costs  65     
               
         Present value of net minimum lease payments included in long-term debt $176     
         
             In connection with past sales of various plants and operations, Marathon assigned and the purchasers assumed certain leases of major equipment used in the divested plants and operations of United States Steel. In the event of a default by any of the purchasers, United States Steel has assumed these obligations; however, Marathon remains

        F-38Outstanding stock-based awards –The following is a summary of stock option award activity.

         
         Number
        of Shares

         Weighted-
        Average
        Exercise Price


        Outstanding at December 31, 2003 9,006,380 $28.33
         Granted 2,067,300  33.28
         Exercised (2,963,546) 17.17
         Canceled (96,886) 30.78
          
           
        Outstanding at December 31, 2004 8,013,248  29.84
         Granted 1,894,720  50.28
         Exercised (3,786,828) 29.37
         Canceled (113,186) 33.96
          
           
        Outstanding at December 31, 2005 6,007,954  36.51
         Granted 1,601,800  75.68
         Exercised (2,018,629) 23.22
         Canceled (95,630) 51.42
          
           
        Outstanding at December 31, 2006(a) 5,495,495  49.43

        (a)
        Of the stock option awards outstanding as of December 31, 2006, 5,076,185 and 419,310 were outstanding under the 2003 Incentive Compensation Plan and 1990 Stock Plan, including 489,691 stock options with tandem SARs.

                The intrinsic value of stock option awards exercised during 2006, 2005 and 2004 was $107 million, $90 million and $27 million. Of those amounts, $32 million, $61 million and $19 million relate to stock options with tandem SARs.


                The following table presents information on stock option awards at December 31, 2006:

         
         Outstanding
         Exercisable
        Range of
        Exercise Prices

         Number
        of Shares
        Under
        Option

         Weighted-Average
        Remaining
        Contractual Life

         Weighted-Average
        Exercise Price

         Number
        of Shares
        Under
        Option

         Weighted-Average
        Exercise Price


        $25.50 – 26.91 556,450 6 $25.53 556,450 $25.53
        $28.12 – 30.88 189,685 5  28.39 189,685  28.39
        $32.52 – 34.00 1,596,430 7  33.51 949,555  33.44
        $47.65 – 51.67 1,568,630 8  50.13 379,244  49.75
        $75.64 – 81.02 1,584,300 9  75.68 –    –  
           
              
           
         Total 5,495,495 8  49.43 2,074,934  33.84

                As of December 31, 2006, the aggregate intrinsic value of stock option awards outstanding was $237 million. The aggregate intrinsic value and weighted average remaining contractual life of stock option awards currently exercisable were $122 million and 7 years. As of December 31, 2006, the number of fully-vested stock option awards and stock option awards expected to vest was 5,061,806. The weighted average exercise price and weighted average remaining contractual life of these stock option awards were $48.52 and 8 years and the aggregate intrinsic value was $223 million. As of December 31, 2006, unrecognized compensation cost related to stock option awards was $32 million, which is expected to be recognized over a weighted average period of 2 years.

                The following is a summary of stock-based performance award and restricted stock award activity.

         
         Stock-Based
        Performance
        Awards

         Weighted Average
        Grant Date Fair
        Value

         Restricted
        Stock Awards

         Weighted Average
        Grant Date Fair
        Value


        Unvested at December 31, 2005 448,600 $29.93 985,556 $47.94
         Granted 67,848(a) 76.82 218,980  80.90
         Vested (273,448) 38.30 (388,597) 41.18
         Forfeited (6,000) 33.61 (39,790) 53.10
          
            
           
        Unvested at December 31, 2006 237,000  33.61 776,149  60.42

        (a)
        Additional shares were issued in 2006 because the performance targets were exceeded for the 36-month performance period related to the 2003 grant.

                During 2006, 2005 and 2004 the weighted average grant date fair value of restricted stock awards was $80.90, $54.41 and $36.55. During 2004, the weighted average grant date fair value of stock-based performance awards was $33.61. The vesting date fair value of stock-based performance awards which vested during 2006, 2005 and 2004 was $21 million, $5 million and $4 million. The vesting date fair value of restricted stock awards which vested during 2006, 2005 and 2004 was $32 million, $13 million and $7 million.

        primarily obligated for payments under these leases. Minimum lease payments under these operating lease obligations of $37 million have been included above and an equal amount has been reported as sublease rentals.
             Of the $176 million present value of net minimum capital lease payments, $115 million was related to obligations assumed by United States Steel under the Financial Matters Agreement. Of the $517 million total minimum operating lease payments, $8 million was assumed by United States Steel under the Financial Matters Agreement.
             During 2005, Marathon renewed the lease for its corporate headquarters in Houston, Texas. Future minimum lease obligations associated with this operating lease are included in the table above.
             During 2003, Marathon purchased two LNG tankers which were previously leased. A $17 million charge was recorded on the termination of the operating leases. These tankers are used to transport LNG from Kenai, Alaska to Tokyo, Japan.

        Operating lease rental expense was:
                     
        (In millions) 2005 2004 2003
         
        Minimum rental $165(a) $168(a) $182(a)
        Contingent rental  21   15   15 
        Sublease rentals  (14)  (12)  (9)
                  
        Net rental expense $172  $171  $188 
         
        (a)Excludes $10 million, $11 million and $23 million paid by United States Steel in 2005, 2004 and 2003 on assumed leases.
                As of December 31, 2006, there was $29 million of unrecognized compensation cost related to stock-based performance awards and restricted stock awards which is expected to be recognized over a weighted average period of two years.

        F-37



        27. Stock Repurchase Program

        On January 29, 2006, Marathon's Board of Directors authorized the repurchase of up to $2 billion of common stock. As of December 31, 2006, the Company had acquired 20.7 million common shares at a cost of $1.698 billion. On January 28, 2007, Marathon's Board of Directors authorized an extension of the share repurchase program by an additional $500 million. Purchases under the program may be in either open market transactions, including block purchases, or in privately negotiated transactions. The Company will use cash on hand, cash generated from operations or cash from available borrowings to acquire shares. This program may be changed based upon our financial condition or changes in market conditions and is subject to termination prior to completion.


        28. Leases

        Marathon leases a wide variety of facilities and equipment under operating leases, including land and building space, office equipment, production facilities and transportation equipment. Most long-term leases include renewal options and, in certain leases, purchase options. Future minimum commitments for capital lease obligations (including sale-leasebacks accounted for as financings) and for operating lease obligations having remaining noncancelable lease terms in excess of one year are as follows:

        (In millions)

         Capital
        Lease
        Obligations

         Operating
        Lease
        Obligations

         

         
        2007 $36 $159 
        2008  27  160 
        2009  27  136 
        2010  28  101 
        2011  27  68 
        Later years  71  259 
        Sublease rentals  –    (32)
          
         
         
         Total minimum lease payments  216 $851 
             
         
        Less imputed interest costs  53    
          
            
         Present value of net minimum lease payments included in long-term debt $163    

         

                In connection with past sales of various plants and operations, Marathon assigned and the purchasers assumed certain leases of major equipment used in the divested plants and operations of United States Steel. In the event of a default by any of the purchasers, United States Steel has assumed these obligations; however, Marathon remains primarily obligated for payments under these leases. Minimum lease payments under these operating lease obligations of $31 million have been included above and an equal amount has been reported as sublease rentals.

                Of the $163 million present value of net minimum capital lease payments, $104 million was related to obligations assumed by United States Steel under the Financial Matters Agreement. Of the $851 million total minimum operating lease payments, $3 million was assumed by United States Steel under the Financial Matters Agreement.

                Operating lease rental expense was:

        (In millions)

         2006
         2005
         2004
         

         
        Minimum rental $197(a)$165(a)$168(a)
        Contingent rental  28  21  15 
        Sublease rentals  (7) (14) (12)
          
         
         
         
         Net rental expense $218 $172 $171 

         
        (a)
        Excludes $9 million, $10 million and $11 million paid by United States Steel in 2006, 2005 and 2004 on assumed leases.

        F-38



        29. Sale of Minority Interests in EGHoldings

        In connection with the formation of Equatorial Guinea LNG Holdings Limited, GEPetrol was given certain contractual rights that gave GEPetrol the option to purchase and resell a 13 percent interest in EGHoldings held by Marathon to a third party. On July 25, 2005, GEPetrol exercised these rights and reimbursed Marathon for its actual costs incurred up to the date of closing, plus an additional specified rate of return. Marathon and GEPetrol entered into agreements under which Mitsui and a subsidiary of Marubeni acquired 8.5 percent and 6.5 percent interests, respectively, in EGHoldings. As part of these agreements, Marathon sold a 2 percent interest in EGHoldings to Mitsui for its actual costs incurred up to the date of closing, plus a specified rate of return, as well as a premium and future consideration based upon the performance of EGHoldings. Following the transaction, Marathon holds a 60 percent interest in EGHoldings, with GEPetrol holding a 25 percent interest and Mitsui and Marubeni holding the remaining interests.
             During 2005, Marathon received net proceeds of $163 million in connection with the transactions and recorded a gain, which is included in other income – net.

        In connection with the formation of Equatorial Guinea LNG Holdings Limited, GEPetrol was given certain contractual rights that gave GEPetrol the option to purchase and resell a 13 percent interest in EGHoldings held by Marathon to a third party. On July 25, 2005, GEPetrol exercised these rights and reimbursed Marathon for its actual costs incurred up to the date of closing, plus an additional specified rate of return. Marathon and GEPetrol entered into agreements under which Mitsui and a subsidiary of Marubeni acquired 8.5 percent and 6.5 percent interests in EGHoldings. As part of these agreements, Marathon sold a 2 percent interest in EGHoldings to Mitsui for its actual costs incurred up to the date of closing, plus a specified rate of return, as well as a premium and future consideration based upon the performance of EGHoldings. Following the transaction, Marathon held a 60 percent interest in EGHoldings, GEPetrol held a 25 percent interest and Mitsui and Marubeni held the remaining interests.

                During 2005, Marathon received net proceeds of $163 million in connection with the transactions and recorded a gain, which is included in other income.


        28.30. Contingencies and Commitments

        Marathon is the subject of, or party to, a number of pending or threatened legal actions, contingencies and commitments involving a variety of matters, including laws and regulations relating to the environment. Certain of these matters are discussed below. The ultimate resolution of these contingencies could, individually or in the aggregate, be material to Marathon’s consolidated financial statements. However, management believes that Marathon will remain a viable and competitive enterprise even though it is possible that these contingencies could be resolved unfavorably.
        Environmental matters – Marathon is subject to federal, state, local and foreign laws and regulations relating to the environment. These laws generally provide for control of pollutants released into the environment and require responsible parties to undertake remediation of hazardous waste disposal sites. Penalties may be imposed for noncompliance. At December 31, 2005 and 2004, accrued liabilities for remediation totaled $103 million and $110 million. It is not presently possible to estimate the ultimate amount of all remediation costs that might be incurred or the penalties that may be imposed. Receivables for recoverable costs from certain states, under programs to assist companies in cleanup efforts related to underground storage tanks at retail marketing outlets, were $68 million and $65 million at December 31, 2005 and 2004, respectively.
             On May 11, 2001, MPC entered into a consent decree with the U.S. Environmental Protection Agency which commits it to complete certain agreed on environmental projects over an eight-year period primarily aimed at reducing air emissions at its seven refineries. The court approved this consent decree on August 28, 2001. The total one-time expenditures for these environmental projects are estimated to be approximately $420 million over the eight-year period, with about $265 million incurred through December 31, 2005. In addition, MPC has nearly completed certain agreed on supplemental environmental projects as part of this settlement of an enforcement action for alleged Clean Air Act violations, at a cost of $9 million. Marathon believes that this settlement will provide the Company with increased permitting and operating flexibility while achieving significant emission reductions.

        F-39Marathon is the subject of, or party to, a number of pending or threatened legal actions, contingencies and commitments involving a variety of matters, including laws and regulations relating to the environment. Certain of these matters are discussed below. The ultimate resolution of these contingencies could, individually or in the aggregate, be material to Marathon's consolidated financial statements. However, management believes that Marathon will remain a viable and competitive enterprise even though it is possible that these contingencies could be resolved unfavorably.

        Environmental matters –Marathon is subject to federal, state, local and foreign laws and regulations relating to the environment. These laws generally provide for control of pollutants released into the environment and require responsible parties to undertake remediation of hazardous waste disposal sites. Penalties may be imposed for noncompliance. At December 31, 2006 and 2005, accrued liabilities for remediation totaled $101 million and $103 million. It is not presently possible to estimate the ultimate amount of all remediation costs that might be incurred or the penalties that may be imposed. Receivables for recoverable costs from certain states, under programs to assist companies in cleanup efforts related to underground storage tanks at retail marketing outlets, were $66 million and $68 million at December 31, 2006 and 2005.

                On May 11, 2001, MPC entered into a consent decree with the U.S. Environmental Protection Agency which commits it to complete certain agreed upon environmental projects over an eight-year period primarily aimed at reducing air emissions at its seven refineries. The court approved this consent decree on August 28, 2001. The total one-time expenditures for these environmental projects are estimated to be approximately $425 million over the eight-year period, with about $365 million incurred through December 31, 2006. In addition, MPC has been working on certain agreed upon supplemental environmental projects as part of this settlement of an enforcement action for alleged CAA violations and these have been substantially completed.

        F-39


        Guarantees– Marathon has issued the following guarantees:
                
            Maximum Potential
            Undiscounted Payments
            as of December 31,
        (In millions) Term 2005
         
        Indebtedness of equity method investees:      
         
        LOCAP(a)
         Perpetual-Loan Balance Varies $23 
         
        LOOP(a)
         2006-2024  160 
         
        Centennial(b)
         2007-2024  75 
        Guarantees/indemnifications related to asset sales:      
         
        Yates(c)
         Indefinite  228 
         
        Canada(d)
         Indefinite  568 
         
        Miscellaneous asset sales(e)
         2006-Indefinite  68 
        Other:      
         
        United States Steel(f)
         2006-2012  651 
         
        Centennial Pipeline catastrophic event(g)
         Indefinite  50 
         
        Alliance Pipeline(h)
         2006-2015  69 
         
        Kenai Kachemak Pipeline LLC(i)
         2006-2017  15 
         
        Corporate assets(j)
         (j)  14 
         
        Mobile transportation equipment leases(k)
         2006-2010  6 
         
        (a)Marathon holds interests in an offshore oil port, LOOP LLC (“LOOP”), and a crude oil pipeline system, LOCAP LLC (“LOCAP”). Both LOOP and LOCAP have secured various project financings with throughput and deficiency agreements. Under the agreements, Marathon is required to advance funds if the investees are unable to service debt. Any such advances are considered prepayments of future transportation charges. The terms of the agreements vary but tend to follow the terms of the underlying debt. Assuming non-payment by the investees, the maximum potential amount of future payments under the guarantees is estimated to be $183 million. Included in these amounts are a LOOP revolving credit facility of $25 million and a LOCAP revolving credit facility of $23 million. The undrawn portion of the revolving credit facilities is $34 million.
        (b)Marathon holds an interest in a refined products pipeline, Centennial Pipeline LLC (“Centennial”), and has guaranteed the repayment of Centennial’s outstanding balance under a Master Shelf Agreement, which expires in 2024, and a Credit Agreement, which expires in 2007. The guarantees arose in order to obtain adequate financing. Prior to expiration of the Master Shelf Agreement, Marathon could be relinquished from responsibility under the guarantee should Centennial meet certain financial tests. If Centennial defaults on its outstanding balance, the estimated maximum potential amount of future payments is $75 million.
        (c)In 2003, Marathon sold its interest in the Yates field and gathering system to Kinder Morgan. In accordance with this transaction, Marathon indemnified Kinder Morgan from inaccuracies in Marathon’s representations, warranties, covenants and agreement. There is not a specified term on these guarantees and the maximum potential amount of future cash payments is estimated at $228 million.
        (d)In conjunction with the sale of certain Canadian assets to Husky Oil Operations Limited (“Husky”) during 2003, Marathon guaranteed Husky with regards to unknown environmental obligations and inaccuracies in representations, warranties, covenants and agreements by Marathon. These indemnifications are part of the normal course of doing business and selling assets. Per the Purchase and Sale Agreement, the maximum potential amount of future payments associated with these guarantees is $568 million.
        (e)Marathon entered into certain performance and general guarantees and environmental and general indemnifications in connection with certain asset sales. The terms vary from 2005 to indefinite and the maximum potential amount of future payments under the guarantees and indemnifications is estimated to be $68 million.
        (f)United States Steel is the sole general partner of Clairton 1314B Partnership, L.P., which owns certain cokemaking facilities formerly owned by United States Steel. Marathon has guaranteed to the limited partners all obligations of United States Steel under the partnership documents. In addition to the commitment to fund operating cash shortfalls of the partnership discussed in Note 3, United States Steel, under certain circumstances, is required to indemnify the limited partners if the partnership product sales fail to qualify for the credit under Section 29 of the Internal Revenue Code. United States Steel has estimated the maximum potential amount of this indemnity obligation, including interest and tax gross-up, was approximately $650 million. Furthermore, United States Steel under certain circumstances has indemnified the partnership for environmental obligations. The maximum potential amount of this indemnity obligation is not estimable.
        (g)The agreement between Centennial and its members allows each member to contribute cash in lieu of Centennial procuring separate insurance in the event of third-party liability arising from a catastrophic event. There is an indefinite term for the agreement and each member is to contribute cash in proportion to its ownership interest, up to a maximum amount of $50 million.
        (h)Marathon is a party to a long-term transportation services agreement with Alliance Pipeline L.P. (“Alliance”). The agreement requires Marathon to pay minimum annual charges of approximately $7 million through 2015. The payments are required even if the transportation facility is not utilized. This contract has been used by Alliance to secure its financing. This agreement runs through 2015 and has a maximum potential payout of $69 million. As a result of the Canadian sale discussed above, Husky has indemnified Marathon for any claims related to these guarantees.
        (i)Marathon is an equity investor in Kenai Kachemak Pipeline LLC (“KKPL”) , holding a 60 percent, noncontrolling interest. In April 2003, Marathon guaranteed KKPL’s performance to properly construct, operate, maintain and abandon the pipeline in accordance with the Alaska Pipeline Act and the Right of Way Lease Agreement with the State of Alaska. The major obligations covered under the guarantee include maintaining the right-of-way, satisfying any liabilities caused by operation of the pipeline, and providing for the abandonment costs. Obligations that could arise under the guarantee would vary according to the circumstances triggering payment but the maximum potential payment is estimated at $15 million.
        (j)Marathon has entered into leases of corporate assets containing general lease indemnities and guaranteed residual value clauses. There is not a specified term and the maximum potential future payment is estimated to be $14 million.
        (k)These leases contain terminal rental adjustment clauses which provide that Marathon will indemnify the lessor to the extent that the proceeds from the sale of the asset at the end of the lease fall short of the specified minimum percentage of the fair market value of the asset at the time of sale.

        F-40Guarantees  –  Marathon has issued the following guarantees:

        (In millions)

         Term
         Maximum Potential
        Undiscounted Payments
        as of December 31, 2006


        Indebtedness of equity method investees:     
         LOOP(a) Through 2024 $160
         LOCAP(a) Perpetual-Loan Balance Varies  23
         Centennial(b) Through 2024  75
        Guarantees/indemnifications related to asset sales:     
         Russia(c) Indefinite  843
         Yates(d) Indefinite  228
         Canada(e) Indefinite  568
         Miscellaneous asset sales(f) Indefinite  68
        Other:     
         United States Steel(g) Through 2012  680
         Centennial Pipeline catastrophic event(h) Indefinite  50
         Alliance Pipeline(i) Through 2015  59
         Kenai Kachemak Pipeline LLC(j) Through 2017  15
         Corporate assets(k) (k)  29

        (a)
        Marathon holds interests in an offshore oil port, LOOP LLC ("LOOP"), and a crude oil pipeline system, LOCAP LLC ("LOCAP"). Both LOOP and LOCAP have secured various project financings with throughput and deficiency agreements. Under the agreements, Marathon is required to advance funds if the investees are unable to service debt. Any such advances are considered prepayments of future transportation charges. The terms of the agreements vary but tend to follow the terms of the underlying debt. Included in the underlying debt are a LOOP revolving credit facility of $25 million and a LOCAP revolving credit facility of $23 million.
        (b)
        Marathon holds an interest in a refined products pipeline, Centennial Pipeline LLC ("Centennial"), and has guaranteed the repayment of Centennial's outstanding balance under a Master Shelf Agreement, which expires in 2024, and a Credit Agreement, which expires in 2007. The guarantees arose in order to obtain adequate financing. Prior to expiration of the Master Shelf Agreement, Marathon could be relinquished from responsibility under the guarantee should Centennial meet certain financial tests.
        (c)
        In conjunction with the sale of its Russian businesses as discussed in Note 7, Marathon guaranteed the purchaser with regard to unknown obligations and inaccuracies in representations, warranties, covenants and agreements by Marathon. These indemnifications are part of the normal course of selling assets. Under the agreement, the maximum potential amount of future payments associated with these guarantees is equivalent to the proceeds from the sale.
        (d)
        In 2003, Marathon sold its interest in the Yates field and gathering system. In accordance with this transaction, Marathon indemnified the purchaser from inaccuracies in Marathon's representations, warranties, covenants and agreements.
        (e)
        In conjunction with the sale of certain Canadian assets during 2003, Marathon guaranteed the purchaser with regards to unknown environmental obligations and inaccuracies in Marathon's representations, warranties, covenants and agreements.
        (f)
        Marathon entered into certain performance and general guarantees and environmental and general indemnifications in connection with certain asset sales.
        (g)
        United States Steel is the sole general partner of Clairton 1314B Partnership, L.P., which owns certain cokemaking facilities formerly owned by United States Steel. Marathon has guaranteed to the limited partners all obligations of United States Steel under the partnership documents. In addition to the commitment to fund operating cash shortfalls of the partnership discussed in Note 3, United States Steel, under certain circumstances, is required to indemnify the limited partners if the partnership's product sales fail to qualify for the credit under Section 29 of the Internal Revenue Code. United States Steel has estimated the maximum potential amount of this indemnity obligation, including interest and tax gross-up, was approximately $680 million. Furthermore, United States Steel under certain circumstances has indemnified the partnership for environmental obligations.
        (h)
        The agreement between Centennial and its members allows each member to contribute cash in lieu of Centennial procuring separate insurance in the event of third-party liability arising from a catastrophic event. Each member is to contribute cash in proportion to its ownership interest.
        (i)
        Marathon is a party to a long-term transportation services agreement with Alliance Pipeline L.P. ("Alliance"). The agreement requires Marathon to pay minimum annual charges of approximately $7 million through 2015. The payments are required even if the transportation facility is not utilized. This contract has been used by Alliance to secure its financing. As a result of the Canadian asset sale discussed above, Husky has indemnified Marathon for any claims related to these guarantees.
        (j)
        Marathon is an equity investor in Kenai Kachemak Pipeline LLC ("KKPL"), holding a 60 percent, noncontrolling interest. In April 2003, Marathon guaranteed KKPL's performance to properly construct, operate, maintain and abandon the pipeline in accordance with the Alaska Pipeline Act and the Right of Way Lease Agreement with the State of Alaska. The major obligations covered under the guarantee include maintaining the right-of-way, satisfying any liabilities caused by operation of the pipeline, and providing for the abandonment costs. Obligations that could arise under the guarantee would vary according to the circumstances triggering payment.
        (k)
        Marathon has entered into leases of corporate assets containing general lease indemnities and guaranteed residual value clauses.

        Contract commitments  –  At December 31, 2006 and 2005, Marathon's contract commitments to acquire property, plant and equipment totaled $1.703 billion and $668 million. The $1.035 billion increase is primarily due to commitments related to the Garyville refinery expansion.


        Agreements with joint owners  –  As part of the formation of PTC, MPC and Pilot Corporation ("Pilot") entered into a Put/Call and Registration Rights Agreement (the "Agreement"). The Agreement provides that any time after

        F-40



        September 1, 2008, Pilot will have the right to sell its interest in PTC to MPC for an amount of cash and/or Marathon, MPC or Ashland equity securities equal to the product of 90 percent (95 percent if paid in securities) of the fair market value of PTC at the time multiplied by Pilot's percentage interest in PTC. At any time after September 1, 2011, under certain conditions, MPC will have the right to purchase Pilot's interest in PTC for an amount of cash and/or Marathon, MPC or Ashland equity securities equal to the product of 105 percent (110 percent if paid in securities) of the fair market value of PTC at the time multiplied by Pilot's percentage interest in PTC. Under the Agreement, MPC would determine the form of consideration to be paid upon exercise of the rights.

        Contract commitments – At December 31, 2005 and 2004, Marathon’s contract commitments to acquire property, plant and equipment totaled $668 million and $1.094 billion, respectively. The $426 million decrease is primarily due to the continued progress of the construction of the Equatorial Guinea LNG plant.
        Agreements with joint owners – As part of the formation of PTC, MPC and Pilot Corporation (“Pilot”) entered into a Put/ Call and Registration Rights Agreement (the “Agreement”). The Agreement provides that any time after September 1, 2008, Pilot will have the right to sell its interest in PTC to MPC for an amount of cash and/or Marathon, MPC or Ashland equity securities equal to the product of 90 percent (95 percent if paid in securities) of the fair market value of PTC at the time multiplied by Pilot’s percentage interest in PTC. At any time after September 1, 2011, under certain conditions, MPC will have the right to purchase Pilot’s interest in PTC for an amount of cash and/or Marathon, MPC or Ashland equity securities equal to the product of 105 percent (110 percent if paid in securities) of the fair market value of PTC at the time multiplied by Pilot’s percentage interest in PTC. Under the Agreement, MPC would determine the form of consideration to be paid upon exercise of the rights.
        29. Subsequent EventOther contingencies
        On January 29, 2006, Marathon’s Board of Directors authorized the repurchase of up to $2 billion of common stock over a period of two years. Such purchases will be made during this period as Marathon’s financial condition and market conditions warrant. Any purchases under the program may be in either open market transactions, including block purchases, or in privately negotiated transactions. The repurchase program does not include specific price targets or timetables, and is subject to termination prior to completion. Marathon will use cash on hand, cash generated from operations, or cash from available borrowings to acquire shares. Shares of common stock repurchased under the program will be held as treasury shares.
          –  In November 2006, the government of Equatorial Guinea enacted a new hydrocarbon law governing petroleum operations in Equatorial Guinea. The transitional provision of the law provides that all contractors and the terms of any contract to which they are a party will be subject to the law. The governmental agency responsible for the energy industry was given the authority to renegotiate any contract for the purpose of adapting any terms and conditions that are inconsistent with the new law. Marathon is in the process of determining what impact this law may have on its existing operations in Equatorial Guinea.


        30.31. Accounting Standards Not Yet Adopted

        In February 2006, the FASB issued SFAS No. 155, “Accounting for Certain Hybrid Financial Instruments – an amendment of FASB Statements No. 133 and 140.” SFAS No. 155 simplifies the accounting for certain hybrid financial instruments, eliminates the FASB’s interim guidance which provides that beneficial interests in securitized financial assets are not subject to the provisions of SFAS No. 133, “Accounting for Derivative Instruments and Hedging Activities,” and eliminates the restriction on the passive derivative instruments that a qualifying special-purpose entity may hold. SFAS No. 155 is effective for all financial instruments acquired or issued after the beginning of an entity’s first fiscal year that begins after September 15, 2006. Marathon is currently studying the provisions of this Statement to determine the impact on its consolidated financial statements.
             In September 2005, the FASB ratified the consensus reached by the Emerging Issues Task Force (“EITF”) on Issue No. 04-13, “Accounting for Purchases and Sales of Inventory with the Same Counterparty.” The issue defines when a purchase and a sale of inventory with the same party that operates in the same line of business is recorded at fair value or considered a single nonmonetary transaction subject to the fair value exception of APB Opinion No. 29. The purchase and sale transactions may be pursuant to a single contractual arrangement or separate contractual arrangements and the inventory purchased or sold may be in the form of raw materials, work-in-process, or finished goods. In general, two or more transactions with the same party are treated as one if they are entered into in contemplation of each other. The rules apply to new arrangements entered into in reporting periods beginning after March 15, 2006. The accounting for certain of the transactions that Marathon considers as matching buy/sell transactions will be affected by this consensus and therefore, upon adoption, these transactions will no longer be recorded on a gross basis. Marathon is currently studying the provisions of this consensus to determine the impact on its consolidated financial statements; however, management does not believe any impact on net income would be material. There will be no impact on cash flows from operations as a result of adoption.
             In May 2005, the FASB issued SFAS No. 154, “Accounting Changes and Error Corrections – A Replacement of APB Opinion No. 20 and FASB Statement No. 3.” SFAS No. 154 requires companies to recognize (1) voluntary changes in accounting principle and (2) changes required by a new accounting pronouncement, when the pronouncement does not include specific transition provisions, retrospectively to prior periods’ financial statements, unless it is impracticable to determine either the period-specific effects or the cumulative effect of the change. SFAS No. 154 is effective for accounting changes and correction of errors made in fiscal years beginning after December 15, 2005.
             In December 2004, the FASB issued SFAS No. 123 (Revised 2004), “Share-Based Payment,” (“SFAS No. 123(R)”) as a revision of SFAS No. 123, “Accounting for Stock-Based Compensation.” This statement requires entities to measure the cost of employee services received in exchange for an award of equity instruments based on the fair value of the award on the grant date. That cost will be recognized over the period during which an employee is required to provide service in exchange for the award, usually the vesting period. In addition, awards classified as liabilities will be remeasured each reporting period. Marathon adopted the fair value method under SFAS No. 123 for grants made, modified or settled on or after January 1, 2003. Accordingly, Marathon does not expect the adoption of SFAS No. 123(R) to have a material effect on its consolidated results of operations, financial position or

        F-41In February 2007, the FASB issued SFAS No. 159, "The Fair Value Option for Financial Assets and Financial Liabilities." This statement permits entities to choose to measure many financial instruments and certain other items at fair value that are not currently required to be measured at fair value. It requires that unrealized gains and losses on items for which the fair value option has been elected be recorded in net income. The statement also establishes presentation and disclosure requirements designed to facilitate comparisons between entities that choose different measurement attributes for similar types of assets and liabilities. For Marathon, SFAS No. 159 will be effective January 1, 2008, and retrospective application is not permitted. Should Marathon elect to apply the fair value option to any eligible items that exist at January 1, 2008, the effect of the first remeasurement to fair value would be reported as a cumulative effect adjustment to the opening balance of retained earnings. Marathon is currently evaluating the provisions of this statement.

                In September 2006, the FASB issued SFAS No. 157, "Fair Value Measurements." This statement defines fair value, establishes a framework for measuring fair value in generally accepted accounting principles and expands disclosures about fair value measurements. SFAS No. 157 does not require any new fair value measurements but may require some entities to change their measurement practices. For Marathon, SFAS No. 157 will be effective January 1, 2008, with early application permitted. Marathon is currently evaluating the provisions of this statement.

                In September 2006, the FASB issued FASB Staff Position ("FSP") No. AUG AIR-1, "Accounting for Planned Major Maintenance Activities." This FSP prohibits the use of the accrue-in-advance method of accounting for planned major maintenance activities in annual and interim financial reporting periods. Marathon expenses such costs in the same annual period as incurred; however, estimated annual major maintenance costs are recognized as expense throughout the year on a pro rata basis. As such, adoption of FSP No. AUG AIR-1 will have no impact on Marathon's annual consolidated financial statements. Marathon is required to adopt the FSP effective January 1, 2007. Marathon does not believe the provisions of FSP No. AUG AIR-1 will have a significant impact on its interim consolidated financial statements.

                In July 2006, the FASB issued FIN No. 48, "Accounting for Uncertainty in Income Taxes – An Interpretation of FASB Statement No. 109." FIN No. 48 clarifies the accounting for uncertainty in income taxes recognized in an enterprise's financial statements in accordance with SFAS No. 109, "Accounting for Income Taxes." FIN No. 48 prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. The new standard also provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, transition and disclosure. For Marathon, the provisions of FIN No. 48 are effective January 1, 2007. Marathon does not believe adoption of this statement will have a significant effect on its consolidated results of operations, financial position or cash flows.

                In March 2006, the FASB issued SFAS No. 156, "Accounting for Servicing of Financial Assets – An Amendment of FASB Statement No. 140." This statement amends SFAS No. 140, "Accounting for Transfers and Servicing of Financial Assets and Extinguishments of Liabilities," with respect to the accounting for separately recognized servicing assets and servicing liabilities. Marathon is required to adopt SFAS No. 156 effective January 1, 2007. Marathon does not expect adoption of this statement to have a significant effect on its consolidated results of operations, financial position or cash flows.

                In February 2006, the FASB issued SFAS No. 155, "Accounting for Certain Hybrid Financial Instruments – An Amendment of FASB Statements No. 133 and 140." SFAS No. 155 simplifies the accounting for certain hybrid financial instruments, eliminates the interim FASB guidance which provides that beneficial interests in securitized financial assets are not subject to the provisions of SFAS No. 133, "Accounting for Derivative Instruments and Hedging Activities," and eliminates the restriction on the passive derivative instruments that a qualifying special-purpose entity may hold. For Marathon, SFAS No. 155 is effective for all financial instruments acquired or issued on or after January 1, 2007. Marathon does not expect adoption of this statement to have a significant effect on its consolidated results of operations, financial position or cash flows.

        F-41


        cash flows. The statement provided for an effective date of July 1, 2005, for Marathon. However, in April 2005, the Securities and Exchange Commission adopted a rule that, for Marathon, deferred the effective date until January 1, 2006. Marathon adopted the provisions of this statement on January 1, 2006.
             In November 2004, the FASB issued SFAS No. 151, “Inventory Costs – an amendment of ARB No. 43, Chapter 4.” This statement requires that items such as idle facility expense, excessive spoilage, double freight, and re-handling costs be recognized as a current-period charge. Marathon is required to implement this statement in the first quarter of 2006. Marathon does not expect the adoption of SFAS No. 151 to have a material effect on its consolidated results of operations, financial position or cash flows.


        Selected Quarterly Financial Data (Unaudited)

                                          
          2005 2004
             
        (In millions, except per share data) 4th Qtr. 3rd Qtr. 2nd Qtr. 1st Qtr. 4th Qtr. 3rd Qtr. 2nd Qtr. 1st Qtr.
         
        Revenues $17,186  $17,174  $16,019  $12,932  $14,183  $12,249  $12,514  $10,652 
        Income from operations  2,052   1,268   1,358   624   821   542   829   478 
        Income from continuing operations  1,284   770   673   324   429   222   348   258 
        Income from discontinued operations  –    –    –    –    –    –    4   –  
        Income before cumulative effect of changes in accounting principle  1,284   770   673   324   429   222   352   258 
        Net income  1,265   770   673   324   429   222   352   258 
         
        Common stock data
                                        
        Net income per share:                                
         – Basic $3.46  $2.11  $1.94  $0.94  $1.24  $0.64  $1.02  $0.83 
         – Diluted $3.43  $2.09  $1.92  $0.93  $1.23  $0.64  $1.02  $0.83 
        Dividends paid per share $0.33  $0.33  $0.28  $0.28  $0.28  $0.25  $0.25  $0.25 
        Price range of common stock(a):
                                        
         – Low $56.28  $54.69  $44.00  $35.73  $36.67  $33.98  $32.22  $30.78 
         – High $69.21  $70.83  $55.58  $48.76  $42.13  $41.52  $37.84  $36.06 
         
        (a)Composite tape

         
         2006
         2005
        (In millions, except per share data)

         4th Qtr.
         3rd Qtr.
         2nd Qtr.
         1st Qtr.
         4th Qtr.
         3rd Qtr.
         2nd Qtr.
         1st Qtr.

        Revenues $13,807 $16,492 $18,179 $16,418 $17,088 $17,077 $15,942 $12,879
        Income from operations  1,793  2,944  2,754  1,476  2,031  1,236  1,351  624
        Income from continuing operations  1,079  1,623  1,484  771  1,265  750  668  323
        Discontinued operations  –    –    264  13  19  20  5  1
        Income before cumulative effect of change in accounting principle  1,079  1,623  1,748  784  1,284  770  673  324
        Net income  1,079  1,623  1,748  784  1,265  770  673  324

        Common stock data                        
        Net income per share:                        
         – Basic $3.09 $4.55 $4.84 $2.15 $3.46 $2.11 $1.94 $0.94
         – Diluted $3.06 $4.52 $4.80 $2.13 $3.43 $2.09 $1.92 $0.93
        Dividends paid per share $0.40 $0.40 $0.40 $0.33 $0.33 $0.33 $0.28 $0.28
        Price range of common stock(a):                        
         – Low $71.94 $70.73 $69.83 $65.24 $56.28 $54.69 $44.00 $35.73
         – High $97.57 $92.19 $86.04 $78.15 $69.21 $70.83 $55.58 $48.76

        (a)
        Composite tape


        Principal Unconsolidated Investees (Unaudited)

        2006
        Ownership

        Company
        Country
        December 31, 2005Activity
        CompanyCountryOwnershipActivity

        Alba Plant LLC Cayman Islands 5252%%(a)LiquifiedLiquefied Petroleum Gas
        Atlantic Methanol Production Company LLC Cayman Islands 4545%%Methanol Production
        Centennial Pipeline LLC United States 5050%%Pipeline & Storage Facility
        Kenai Kachemak Pipeline, LLC United States 6060%%(a)Natural Gas Transmission
        Kenai LNG Corporation United States 3030%%Natural Gas Liquefaction
        LOCAP LLC United States 5959%%(a)Pipeline & Storage Facilities
        LOOP LLC United States 5151%%(a)Offshore Oil Port
        Minnesota Pipe Line Company, LLC United States 1733%%Pipeline Facility
        Muskegon Pipeline LLC United States 6060%%(a)Pipeline Facility
        Odyssey Pipeline L.L.C. United States 2929%%Pipeline Facility
        Pilot Travel Centers LLC United States 5050%%Travel Centers
        Poseidon Oil Pipeline Company, L.L.C. United States 2828%%Crude Oil Transportation
        Southcap Pipe Line Company United States 2222%%Crude Oil Transportation

        (a)Represents a noncontrolling interest.
        (a)
        Represents a noncontrolling interest.

        F-42

        F-42



        Supplementary Information on Oil and Gas Producing Activities (Unaudited)

                The supplementalsupplementary information is disclosed by the following geographic areas: the United States; Europe, which primarily includes activities in the United Kingdom, Ireland and Norway; Africa, which primarily includes activities in Angola, Equatorial Guinea, Gabon and Libya; and Other International, which includes activities in Canada, the Russian Federation and other international locations outside of Europe and Africa.

        Discontinued operations represent Marathon's Russian oil exploration and production businesses that were sold in 2006.


        Capitalized Costs and Accumulated Depreciation, Depletion and Amortization

                                
          United     Other  
        (In millions)December 31     States Europe Africa Int’l Total
         
        2005 Capitalized costs:
                            
          Proved properties $7,015  $6,349  $1,897  $342  $15,603 
          Unproved properties  428   107   573   193   1,301 
          Suspended exploratory wells  111   31   204   17   363 
                        
           Total  7,554   6,487   2,674   552   17,267 
                        
         Accumulated depreciation, depletion and amortization:                    
          Proved properties  4,752   4,476   288   111   9,627 
          Unproved properties  27   –    9   32   68 
                        
           Total  4,779   4,476   297   143   9,695 
                        
         Net capitalized costs $2,775  $2,011  $2,377  $409  $7,572 
         Share of equity method investees’ capitalized costs $13  $–   $395  $–   $408 
         
        2004 Capitalized costs:                    
          Proved properties $6,508  $5,689  $1,376  $231  $13,804 
          Unproved properties  454   115   181   215   965 
          Suspended exploratory wells  115   15   174   35   339 
                        
           Total  7,077   5,819   1,731   481   15,108 
                        
         Accumulated depreciation, depletion and amortization:                    
          Proved properties  4,432   4,209   201   55   8,897 
          Unproved properties  22   –    9   33   64 
                        
           Total  4,454   4,209   210   88   8,961 
                        
         Net capitalized costs $2,623  $1,610  $1,521  $393  $6,147 
         Share of equity method investees’ capitalized costs $14  $–   $377  $–   $391 
         
        (a)Includes capitalized asset retirement costs and the associated accumulated amortization.
        (a)

        (In millions)                                                              December 31
         United
        States

         Europe
         Africa
         Other
        Int'l

         Total

        2006 Capitalized costs:               
          Proved properties $7,682 $7,216 $2,319 $1 $17,218
          Unproved properties  938  77  206  4  1,225
          Suspended exploratory wells  156  25  289  –    470
          
         
         
         
         
           Total  8,776  7,318  2,814  5  18,913
          
         
         
         
         
         Accumulated depreciation, depletion and amortization:               
          Proved properties  5,141  4,771  412  1  10,325
          Unproved properties  42  1  9  –    52
          
         
         
         
         
           Total  5,183  4,772  421  1  10,377
          
         
         
         
         
         Net capitalized costs $3,593 $2,546 $2,393 $4 $8,536
         Share of equity method investees' capitalized costs $15 $–   $361 $–   $376

        2005 Capitalized costs:               
          Proved properties $7,015 $6,349 $1,857 $342 $15,563
          Unproved properties  428  107  573  193  1,301
          Suspended exploratory wells  111  31  204  17  363
          
         
         
         
         
           Total  7,554  6,487  2,634  552  17,227
          
         
         
         
         
         Accumulated depreciation, depletion and amortization:               
          Proved properties  4,752  4,476  288  111  9,627
          Unproved properties  27  –    9  32  68
          
         
         
         
         
           Total  4,779  4,476  297  143  9,695
          
         
         
         
         
         Net capitalized costs $2,775 $2,011 $2,337 $409 $7,532
         Share of equity method investees' capitalized costs $13 $–   $395 $–   $408

        (a)
        Includes capitalized asset retirement costs and the associated accumulated amortization.


        Costs Incurred for Property Acquisition, Exploration and Development
        (a)

                                        
          United     Other Continuing Discontinued  
        (In millions) States Europe Africa Int’l Operations Operations Total
         
        2005 Property acquisition:
                                    
          Proved $3  $–   $390  $–   $393  $–   $393 
          Unproved  31   –    381   –    412   –    412 
         Exploration  186   48   95   24   353   –    353 
         Development  465   531   32   85   1,113   –    1,113 
         
        Capitalized asset retirement costs(b)
          35   108   12   3   158   –    158 
                              
           Total  720   687   910   112   2,429   –    2,429 
         Share of investees’ costs incurred  –    –    31   –    31   –    31 
         
        2004 Property acquisition:                            
          Proved $9  $–   $3  $–   $12  $–   $12 
          Unproved  10   –    1   –    11   –    11 
         Exploration  96   27   127   41   291   –    291 
         Development  316   151   140   102   709   –    709 
         
        Capitalized asset retirement costs(b)
          14   49   5   (5)  63   –    63 
                              
           Total  445   227   276   138   1,086   –    1,086 
         Share of investees’ costs incurred  1   –    128   1   130   –    130 
         
        2003 Property acquisition:                            
          Proved $1  $1  $–   $66  $68  $–   $68 
          Unproved  5   3   1   244   253   –    253 
         Exploration  114   35   53   29   231   17   248 
         Development  266   148   352   33   799   26   825 
         
        Capitalized asset retirement costs(b)(c)
          9   47   3   14   73   –    73 
                              
           Total  395   234   409   386   1,424   43   1,467 
         Share of investees’ costs incurred  29   4   80   12   125   –    125 
         
        (a)Includes costs incurred whether capitalized or expensed.
        (b)Includes the effect of foreign currency fluctuations.
        (c)Excludes $161 million cumulative effect of adopting SFAS No. 143.

        (In millions)

         United
        States

         Europe
         Africa
         Other
        Int'l

         Continuing
        Operations

         Discontinued
        Operations

         Total

        2006 Property acquisition:                     
          Proved $4 $–   $19 $–   $23 $–   $23
          Unproved  526  3  3  4  536  –    536
         Exploration  224  36  169  70  499  2  501
         Development(b)  603  607  40  –    1,250  43  1,293
         Capitalized asset retirement costs(c)  78  201  13  2  294  1  295
          
         
         
         
         
         
         
           Total $1,435 $847 $244 $76 $2,602 $46 $2,648
         Share of investees' costs incurred $3 $–   $1 $–   $4 $–   $4

        2005 Property acquisition:                     
          Proved $3 $–   $390 $–   $393 $–   $393
          Unproved  31  –    381  –    412  –    412
         Exploration  186  48  95  14  343  10  353
         Development(b)  465  531  32  –    1,028  85  1,113
         Capitalized asset retirement costs(c)  35  108  12  1  156  2  158
          
         
         
         
         
         
         
           Total $720 $687 $910 $15 $2,332 $97 $2,429
         Share of investees' costs incurred  –    –    31  –    31  –    31

        2004 Property acquisition:                     
          Proved $9 $–   $3 $–   $12 $–   $12
          Unproved  10  –    1  –    11  –    11
         Exploration  96  27  127  31  281  10  291
         Development(b)  316  151  140  –    607  102  709
         Capitalized asset retirement costs(c)  14  49  5  –    68  (5) 63
          
         
         
         
         
         
         
           Total $445 $227 $276 $31 $979 $107 $1,086
         Share of investees' costs incurred $1 $–   $128 $–   $129 $1 $130

        (a)
        Includes costs incurred whether capitalized or expensed.
        (b)
        Includes $12 million, $12 million and $8 million of costs incurred prior to assignment of proved reserves in 2006, 2005 and 2004. The associated reserves were awaiting full project sanction at the end of the applicable year.
        (c)
        Includes the effect of foreign currency fluctuations.

        F-43


        Supplementary Information on Oil and Gas Producing Activities (Unaudited)CONTINUED
        Results of Operations for Oil and Gas Producing Activities
                               
          United     Other  
        (In millions) States Europe Africa Int’l Total
         
        2005
         Revenues and other income:                    
            Sales(a) $2,227  $1,136  $71  $165  $3,599 
            Transfers  422   38   810   161   1,431 
            Other income(b)  22   –    –    –    22 
                          
              Total revenues  2,671   1,174   881   326   5,052 
          Expenses:                    
            Production costs  (448)  (170)  (82)  (197)  (897)
            Transportation costs(c)  (114)  (40)  (27)  (13)  (194)
            Exploration expenses  (118)  (31)  (27)  (43)  (219)
            Depreciation, depletion and amortization(d)  (411)  (255)  (87)  (56)  (809)
            Administrative expenses  (34)  (8)  (5)  (25)  (72)
                          
              Total expenses  (1,125)  (504)  (228)  (334)  (2,191)
          Other production-related income(f)  2   44   –    –    46 
                          
          Results before income taxes  1,548   714   653   (8)  2,907 
          Income taxes(g)  555   249   193   3   1,000 
                          
          Results of continuing operations $993  $465  $460  $(11) $1,907 
          Share of equity method investees’ results of operations $–   $–   $50  $–   $50 
         
        2004 Revenues and other income:                    
            Sales(a) $1,631  $876  $260  $56  $2,823 
            Transfers  392   28   159   75   654 
                          
              Total revenues  2,023   904   419   131   3,477 
          Expenses:                    
            Production costs  (381)  (166)  (55)  (96)  (698)
            Transportation costs(c)  (112)  (35)  (6)  (7)  (160)
            Exploration expenses  (79)  (19)  (28)  (44)  (170)
            Depreciation, depletion and amortization(d)  (356)  (275)  (56)  (26)  (713)
            Impairments(e)  –    –    –    (44)  (44)
            Administrative expenses  (39)  (4)  (15)  (24)  (82)
                          
              Total expenses  (967)  (499)  (160)  (241)  (1,867)
          Other production-related income(f)  –    15   –    –    15 
                          
          Results before income taxes  1,056   420   259   (110)  1,625 
          Income taxes (credits)(g)  378   156   97   (28)  603 
                          
          Results of continuing operations $678  $264  $162  $(82) $1,022 
          Share of equity method investees’ results of operations $1  $–   $9  $1  $11 
         
        2003 Revenues and other income:                    
            Sales(a) $1,777  $728  $139  $43  $2,687 
            Transfers  424   20   127   24   595 
            Other income (loss)(b)  (88)  65   (1)  –    (24)
                          
              Total revenues  2,113   813   265   67   3,258 
          Expenses:                    
            Production costs  (410)  (136)  (55)  (53)  (654)
            Transportation costs(c)  (120)  (32)  (5)  (3)  (160)
            Exploration expenses  (118)  (18)  (15)  (28)  (179)
            Depreciation, depletion and amortization(d)(h)  (407)  (227)  (42)  (11)  (687)
            Impairments(e)  (3)  –    –    –    (3)
            Administrative expenses  (43)  (17)  (4)  (36)  (100)
                          
              Total expenses  (1,101)  (430)  (121)  (131)  (1,783)
          Other production-related income(f)  1   26   –    –    27 
                          
          Results before income taxes  1,013   409   144   (64)  1,502 
          Income taxes (credits)(g)  352   146   4   (27)  475 
                          
          Results of continuing operations $661  $263  $140  $(37) $1,027 
          Results of discontinued operations $–   $–   $–   $41  $41 
          Share of equity method investees’ results of operations $8  $4  $6  $–   $18 
         
        (a)Excludes noncash effects of changes in the fair value of certain long-term gas sales contracts in the United Kingdom.
        (b)Includes net gains (losses) on asset dispositions.
        (c)Includes the cost to prepare and move liquid hydrocarbons and natural gas to their points of sale.
        (d)Includes accretion of interest on asset retirement obligations.
        (e)Includes impairment of unproved and producing oil and gas properties.
        (f)Includes revenues, net of associated costs, from third-party activities that are an integral part of Marathon’s production operations which may include the processing and/or transportation of third-party production, and the purchase and subsequent resale of gas utilized in reservoir management.
        (g)Computed by adjusting results before income taxes by nontaxable and nondeductible items and multiplying the result by the 35 percent statutory rate and adjusting for applicable tax credits.
        (h)Excludes the cumulative effect on net income of the adoption of SFAS No. 143.

        (In millions)

         United
        States

         Europe
         Africa
         Other
        Int'l

         Total
         

         
        2006 Revenues and other income:                
          Sales(a) $2,329 $1,240 $1,300 $–   $4,869 
          Transfers  307  58  1,168  –    1,533 
          Other income(b)  3  –    –    46  49 
          
         
         
         
         
         
            Total revenues  2,639  1,298  2,468  46  6,451 
         Expenses:                
          Production costs  (512) (207) (126) –    (845)
          Transportation costs(c)  (124) (44) (33) –    (202)
          Exploration expenses  (169) (29) (91) (73) (362)
          Depreciation, depletion and amortization  (458) (281) (127) –    (866)
          Administrative expenses  (41) (10) (6) (36) (92)
          
         
         
         
         
         
            Total expenses  (1,304) (571) (383) (109) (2,367)
         Other production-related income(d)  –    73  1  –    74 
          
         
         
         
         
         
         Results before income taxes  1,335  800  2,086  (63) 4,158 
         Income tax provision (benefit)  489  358  1,457  (4) 2,300 
          
         
         
         
         
         
         Results of continuing operations $846 $442 $629 $(59)$1,858 
         Results of discontinued operations $–   $–   $–   $273 $273 
         Share of equity method investees' results of operations $–   $–   $118 $–   $118 

         
        2005 Revenues and other income:                
          Sales(a) $2,227 $1,136 $71 $–   $3,434 
          Transfers  422  38  810  –    1,270 
          Other income(b)  22  –    –    –    22 
          
         
         
         
         
         
            Total revenues  2,671  1,174  881  –    4,726 
         Expenses:                
          Production costs  (448) (170) (82) (3) (703)
          Transportation costs(c)  (114) (40) (27) –    (181)
          Exploration expenses  (118) (31) (27) (38) (214)
          Depreciation, depletion and amortization  (411) (255) (87) –    (753)
          Administrative expenses  (34) (8) (5) (25) (72)
          
         
         
         
         
         
            Total expenses  (1,125) (504) (228) (66) (1,923)
         Other production-related income(d)  2  44  –    –    46 
          
         
         
         
         
         
         Results before income taxes  1,548  714  653  (66) 2,849 
         Income tax provision (benefit)  572  256  199  (13) 1,014 
          
         
         
         
         
         
         Results of continuing operations $976 $458 $454 $(53)$1,835 
         Results of discontinued operations $–   $–   $–   $42 $42 
         Share of equity method investees' results of operations $–   $–   $50 $–   $50 

         
        2004 Revenues and other income:                
          Sales(a) $1,631 $876 $260 $–   $2,767 
          Transfers  392  28  159  –    579 
          
         
         
         
         
         
            Total revenues  2,023  904  419  –    3,346 
         Expenses:                
          Production costs  (381) (166) (55) (5) (607)
          Transportation costs(c)  (112) (35) (6) –    (153)
          Exploration expenses  (79) (19) (28) (32) (158)
          Depreciation, depletion and amortization  (356) (275) (56) –    (687)
          Administrative expenses  (39) (4) (15) (24) (82)
          
         
         
         
         
         
            Total expenses  (967) (499) (160) (61) (1,687)
         Other production-related income(d)  –    15  –    –    15 
          
         
         
         
         
         
         Results before income taxes  1,056  420  259  (61) 1,674 
         Income tax provision (benefit)  374  154  96  (26) 598 
          
         
         
         
         
         
         Results of continuing operations $682 $266 $163 $(35)$1,076 
         Results of discontinued operations $–   $–   $–   $(47)$(47)
         Share of equity method investees' results of operations included in continuing operations $1 $–   $9 $–   $10 
         Share of equity method investees' results of operations included in discontinued operations $–   $–   $–   $1 $1 

         
        (a)
        Excludes noncash effects of changes in the fair value of certain long-term natural gas sales contracts in the United Kingdom.
        (b)
        Includes net gains on asset dispositions.
        (c)
        Includes the cost to prepare and move liquid hydrocarbons and natural gas to their points of sale.
        (d)
        Includes revenues, net of associated costs, from activities that are an integral part of Marathon's production operations which may include processing and/or transportation of third-party production, the purchase and subsequent resale of natural gas utilized for reservoir management and providing storage capacity.

        F-44


        Supplementary Information on Oil and Gas Producing Activities (Unaudited)CONTINUED
        Results of Operations for Oil and Gas Producing Activities

                The following reconciles results of continuing operations for oil and gas producing activities to E&P segment income:

                      
        (In millions) 2005 2004 2003
         
        Results before income taxes $2,907  $1,625  $1,502 
        Items not included in results of continuing oil and gas operations:            
         Marketing income and technology costs  17   16   24 
         Income from equity method investments  67   12   20 
         Other  (3)  (1)  (5)
        Items not allocated to E&P segment income:            
         Impairment of certain unproved and producing oil and gas properties  –    44   –  
         Gain on asset disposition  –    –    (85)
         Loss on joint venture dissolution  –    –    124 
                     
         E&P segment income $2,988  $1,696  $1,580 
         

        (In millions)

         2006
         2005
         2004
         

         
        Results of continuing operations $1,858 $1,835 $1,076 
        Items not included in results of continuing oil and gas operations, net of tax:          
         Marketing income and technology costs  40  4  4 
         Income from equity method investments  135  52  11 
         Other  1  (4) (1)
        Items not allocated to E&P segment income:          
         Gain on asset disposition  (31) –    –   
          
         
         
         
         E&P segment income $2,003 $1,887 $1,090 

         


        Average Production Costs
        (a)

                             
          United     Other  
          States Europe Africa Int’l Total
         
        2005
         $7.11  $6.45  $3.33  $20.35  $7.26 
        2004  5.58   5.39   3.35   16.76   5.75 
        2003  4.92   4.35   3.98   14.56   4.95 
         
        (a)

        (per boe)

         United
        States

         Europe
         Africa
         Continuing
        Operations


        2006 $8.51 $8.36 $2.78 $6.48
        2005  7.11  6.45  3.33  6.18
        2004  5.58  5.39  3.35  5.25

        (a)
        Computed using production costs, excluding transportation costs, as disclosed in the Results of Operations for Oil and Gas Activities and as defined by the Securities and Exchange Commission. Natural gas volumes were converted to barrels of oil equivalent using a conversion factor of six mcf of natural gas to one barrel of oil.
        Average Sales Prices
                                  
          United     Other Continuing Discontinued
          States Europe Africa Int’l Operations Operations
         
        (excluding derivative gains and losses)
                                
        2005 Liquid hydrocarbons (per bbl)
         $45.41  $52.99  $46.27  $33.47  $45.42  $–  
         
           Natural gas (per mcf)(a)
          6.42   5.72   0.25   –    5.61   –  
        2004 Liquid hydrocarbons (per bbl) $32.76  $37.16  $35.11  $22.65  $33.31  $–  
                 Natural gas (per mcf)(a)
          4.89   4.11   0.25   –    4.31   –  
        2003 Liquid hydrocarbons (per bbl) $26.92  $28.50  $26.29  $18.33  $26.72  $28.96 
                 Natural gas (per mcf)(a)
          4.53   3.32   0.25   –    3.96   5.43 
        (including derivative gains and losses)
                                
        2005 Liquid hydrocarbons (per bbl)
         $45.41  $52.99  $46.27  $33.47  $45.42  $–  
                 Natural gas (per mcf)(a)
          6.40   5.72   0.25   –    5.59   –  
        2004 Liquid hydrocarbons (per bbl) $29.11  $33.65  $35.11  $22.62  $30.73  $–  
                 Natural gas (per mcf) (a)  4.85   4.11   0.25   –    4.28   –  
        2003 Liquid hydrocarbons (per bbl) $26.09  $27.27  $26.29  $18.33  $25.96  $28.96 
                 Natural gas (per mcf)(a)
          4.31   3.32   0.25   –    3.81   5.43 
         
        (a) Excludes the resale of purchased gas utilized in reservoir management.

        F-45


        Supplementary Information on Oil and Gas Producing Activities (Unaudited)and as defined by the Securities and Exchange Commission. Natural gas volumes were converted to barrels of oil equivalent using a conversion factor of six mcf of natural gas to one barrel of oil.

        CONTINUED

        Average Realizations

         
         United
        States

         Europe
         Africa
         Continuing
        Operations

         Discontinued
        Operations


        (excluding derivative gains and losses)               
        2006 Liquid hydrocarbons (per bbl) $54.41 $64.02 $59.83 $58.63 $38.38
         Natural gas (per mcf)(a)  5.76  6.78  0.27  5.52  –  

        2005 Liquid hydrocarbons (per bbl)

         

        $

        45.41

         

        $

        52.99

         

        $

        46.27

         

        $

        47.35

         

        $

        33.47
         
        Natural gas (per mcf)(a)

         

         

        6.42

         

         

        5.72

         

         

        0.25

         

         

        5.61

         

         

        –  

        2004: Liquid hydrocarbons (per bbl)

         

        $

        32.76

         

        $

        37.16

         

        $

        35.11

         

        $

        34.40

         

        $

        22.65
         
        Natural gas (per mcf)(a)

         

         

        4.89

         

         

        4.11

         

         

        0.25

         

         

        4.31

         

         

        –  

        (including derivative gains and losses)

         

         

         

         

         

         

         

         

         

         

         

         

         

         

         
        2006Liquid hydrocarbons (per bbl) $54.41 $64.02 $59.83 $58.63 $38.38
         
        Natural gas (per mcf)(a)

         

         

        5.77

         

         

        6.78

         

         

        0.27

         

         

        5.53

         

         

        –  

        2005 Liquid hydrocarbons (per bbl)

         

        $

        45.41

         

        $

        52.99

         

        $

        46.27

         

        $

        47.35

         

        $

        33.47
         
        Natural gas (per mcf)(a)

         

         

        6.40

         

         

        5.72

         

         

        0.25

         

         

        5.59

         

         

        –  

        2004 Liquid hydrocarbons (per bbl)

         

        $

        29.11

         

        $

        33.65

         

        $

        35.11

         

        $

        31.56

         

        $

        22.62
         
        Natural gas (per mcf)(a)

         

         

        4.85

         

         

        4.11

         

         

        0.25

         

         

        4.28

         

         

        –  

        (a)
        Excludes the resale of purchased natural gas utilized for reservoir management.

        F-45



        Estimated Quantities of Proved Oil and Gas Reserves

                Estimates of the proved reserves have been prepared by internal assetin-house teams includingof reservoir engineers and geoscience professionals. Reserve estimates are periodically reviewed by Marathon’sMarathon's Corporate Reserves groupGroup to assure that rigorous professional standards and the reserves definitions prescribed by the U. S.U.S. Securities and Exchange Commission (SEC)("SEC") are consistently applied throughout the company.

        Company.

                Proved reserves are the estimated quantities of oil and natural gas that geologic and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions. Estimates of proved reserves may change, either positively or negatively, as additional information becomes available and as contractual, economic and political conditions change.

             Marathon’s

                Marathon's net proved reserve estimates have been adjusted as necessary to considerreflect all contractual agreements, royalty obligations and interests owned by others at the time of the estimate. Only reserves that are estimated to be recovered during the term of the current contract have been included in the proved reserve estimate unless there is a clear and consistent history of contract extension. Reserves from properties governed by production sharing contracts have been calculated using the “economic interest”"economic interest" method prescribed by the SEC. Reserves that are not currently considered proved, such as those that may result from extensions of currently proved areas or that may result from applying secondary or tertiary recovery processes not yet tested and determined to be economic are excluded. Purchased natural gas utilized in reservoir management and subsequently resold is also excluded. Marathon does not have any quantities of oil and gas reserves subject to long-term supply agreements with foreign governments or authorities in which Marathon acts as producer.

                Proved developed reserves are the quantities of oil and gas expected to be recovered through existing wells with existing equipment and operating methods. In some cases, proved undeveloped reserves may require substantial new investments in additional wells and related facilities. Production volumes shown are sales volumes, net of any products consumed during production activities.

                                  
          United     Other Continuing Discontinued
          States Europe Africa(a) Int’l Operations Operations
         
        Liquid Hydrocarbons (Millions of barrels)
                                
        Proved developed and undeveloped reserves:
                                
         Beginning of year – 2003  245   76   203   3   527   10 
         
        Purchase of reserves in place(b)
          –    –    –    64   64   –  
         
        Exchange of reserves in place(c)
          173   –    –    –    173   –  
         Revisions of previous estimates  –    (4)  25   11   32   –  
         Improved recovery  4   –    –    4   8   –  
         Extensions, discoveries and other additions  10   2   –    14   26   –  
         Production  (39)  (15)  (10)  (4)  (68)  (1)
         
        Sales of reserves in place(b)
          (183)  –    –    (3)  (186)  (9)
                           
         End of year – 2003  210   59   218   89   576   –  
         
        Purchase of reserves in place(b)
          1   –    2   –    3   –  
         Revisions of previous estimates  (1)  3   14   (51)  (35)  –  
         Improved recovery  1   –    –    –    1   –  
         Extensions, discoveries and other additions  9   60   1   7   77   –  
         Production  (29)  (15)  (12)  (6)  (62)  –  
         
        Sales of reserves in place(b)
          –    –    –    –    –    –  
                           
         End of year – 2004  191   107   223   39   560   –  
         
        Purchase of reserves in place(b)
          –    –    3   –    3   –  
         Re-entry to Libya concessions  –    –    165   –    165   –  
         Revisions of previous estimates  10   4   1   3   18   –  
         Improved recovery  2   –    –    –    2   –  
         Extensions, discoveries and other additions  15   –    –    12   27   –  
         Production  (28)  (13)  (19)  (10)  (70)  –  
         
        Sales of reserves in place(b)
          (1)  –    –    –    (1)  –  
                           
         
        End of year –2005
          189   98   373   44   704   –  
         
        Proved developed reserves:                        
         Beginning of year – 2003  226   63   113   2   404   9 
         End of year – 2003  193   47   120   31   391   –  
         End of year – 2004  171   41   147   27   386   –  
         
        End of year –2005
          165   39   368   31   603   –  
         

        (Millions of barrels)

         United
        States

         Europe
         Africa(a)
         Continuing
        Operations

         Discontinued
        Operations

         

         
        Liquid Hydrocarbons           
        Proved developed and undeveloped reserves:           
         Beginning of year – 2004 210 59 218 487 89 
         Purchase of reserves in place(b) 1 –   2 3 –   
         Revisions of previous estimates (1)3 14 16 (51)
         Improved recovery 1 –   –   1 –   
         Extensions, discoveries and other additions 9 60 1 70 7 
         Production (29)(15)(12)(56)(6)
          
         
         
         
         
         
         End of year – 2004 191 107 223 521 39 
         Purchase of reserves in place(b) –   –   3 3 –   
         Re-entry to Libya concessions –   –   165 165 –   
         Revisions of previous estimates 10 4 1 15 3 
         Improved recovery 2 –   –   2 –   
         Extensions, discoveries and other additions 15 –   –   15 12 
         Production (28)(13)(19)(60)(10)
         Sales of reserves in place(b) (1)–   –   (1)–   
          
         
         
         
         
         
         End of year – 2005 189 98 373 660 44 
         Purchase of reserves in place(b) –   –   1 1 –   
         Revisions of previous estimates 2 8 49 59 1 
         Improved recovery 3 –   –   3 –   
         Extensions, discoveries and other additions 6 15 15 36 4 
         Production (28)(13)(41)(82)(4)
         Sales of reserves in place(b) –   –   –   –   (45)
          
         
         
         
         
         
         End of year –2006 172 108 397 677 –   

         
        Proved developed reserves:           
         Beginning of year – 2004 193 47 120 360 31 
         End of year – 2004 171 41 147 359 27 
         End of year – 2005 165 39 368 572 31 
         End of year –2006 150 35 381 566 –   

         

        F-46


        Supplementary Information on Oil and Gas Producing Activities (Unaudited)CONTINUED
        Estimated Quantities of Proved Oil and Gas Reserves (continued)
                                  
          United     Other Continuing Discontinued
          States Europe Africa(a) Int’l Operations Operations
         
        Share of equity method investees’ proved developed and undeveloped reserves:
                                
         Beginning of year – 2003  183   –    –    –    183   –  
         End of year – 2003  –    –    –    2   2   –  
         
        Proved developed reserves:                      –  
         Beginning of year – 2003  177   –    –    –    177   –  
         End of year – 2003  –    –    –    2   2   –  
         
        Natural Gas (Billions of cubic feet)
                                
        Proved developed and undeveloped reserves:
                                
         Beginning of year – 2003  1,724   562   653   –    2,939   379 
         
        Purchase of reserves in place(b)
          7   –    –    –    7   –  
         Revisions of previous estimates  20   (7)  36   –    49   –  
         Extensions, discoveries and other additions  161   24   –    –    185   8 
         
        Production(d)
          (267)  (95)  (24)  –    (386)  (27)
         
        Sales of reserves in place(b)
          (10)  –    –    –    (10)  (360)
                           
         End of year – 2003  1,635   484   665   –    2,784   –  
         
        Purchase of reserves in place(b)
          1   –    –    –    1   –  
         Revisions of previous estimates  (230)  7   916   –    693   –  
         Extensions, discoveries and other additions  189   150   11   –    350   –  
         
        Production(d)
          (231)  (97)  (28)  –    (356)  –  
         
        Sales of reserves in place(b)
          –    –    –    –    –    –  
                           
         End of year – 2004  1,364   544   1,564   –    3,472   –  
         
        Purchase of reserves in place(b)
          –    –    24   –    24   –  
         Revisions of previous estimates  (78)  18   298   –    238   –  
         Extensions, discoveries and other additions  135   3   –    –    138   –  
         
        Production(d)
          (211)  (79)  (34)  –    (324)  –  
         
        Sales of reserves in place(b)
          (1)  –    –    –    (1)  –  
                           
         
        End of year –2005
          1,209   486   1,852   –    3,547   –  
         
        Proved developed reserves:                        
         Beginning of year – 2003  1,206   408   552   –    2,166   290 
         End of year – 2003  1,067   421   528   –    2,016   –  
         End of year – 2004  992   376   570   –    1,938   –  
         
        End of year –2005
          943   326   638   –    1,907   –  
         
        Share of equity method investees’ proved developed and undeveloped reserves:
                                
         Beginning of year – 2003  –    59   –    –    59   –  
         
        Proved developed reserves:                        
         Beginning of year – 2003  –    36   –    –    36   –  
         
        (a)Consists of estimated reserves from properties governed by production sharing contracts.
        (b)The net positive or negative balance of proved reserves acquired or relinquished in property trades within the same geographic area is reported as purchases of reserves in place or sales of reserves in place, respectively.
        (c)Reserves represent the transfer of certain mineral interests on the dissolution of MKM Partners, L.P.
        (d)Excludes the resale of purchased gas utilized in reservoir management.

        (Billions of cubic feet)

         United
        States

         Europe
         Africa(a)
         Continuing
        Operations

         Discontinued
        Operations


        Natural Gas          
        Proved developed and undeveloped reserves:          
         Beginning of year – 2004 1,635 484 665 2,784 –  
         Purchase of reserves in place(b) 1 –   –   1 –  
         Revisions of previous estimates (230)7 916 693 –  
         Extensions, discoveries and other additions 189 150 11 350 –  
         Production(c) (231)(97)(28)(356)–  
          
         
         
         
         
         End of year – 2004 1,364 544 1,564 3,472 –  
         Purchase of reserves in place(b) –   –   24 24 –  
         Revisions of previous estimates (78)18 298 238 –  
         Extensions, discoveries and other additions 135 3 –   138 –  
         Production(c) (211)(79)(34)(324)–  
         Sales of reserves in place(b) (1)–   –   (1)–  
          
         
         
         
         
         End of year – 2005 1,209 486 1,852 3,547 –  
         Purchase of reserves in place(b) –   4 8 12 –  
         Revisions of previous estimates (5)4 139 138 –  
         Extensions, discoveries and other additions 59 20 24 103 –  
         Production(c) (194)(70)(26)(290)–  
          
         
         
         
         
         End of year –2006 1,069 444 1,997 3,510 –  

        Proved developed reserves:          
         Beginning of year – 2004 1,067 421 528 2,016 –  
         End of year – 2004 992 376 570 1,938 –  
         End of year – 2005 943 326 638 1,907 –  
         End of year –2006 857 238 648 1,743 –  

        (a)
        Consists of estimated reserves from properties governed by production sharing contracts.
        (b)
        The net positive or negative balance of proved reserves acquired or relinquished in property trades within the same geographic area is reported as purchases of reserves in place or sales of reserves in place, respectively.
        (c)
        Excludes the resale of purchased gas utilized in reservoir management.

        F-47


        Supplementary Information on Oil and Gas Producing Activities (Unaudited)CONTINUED
        Standardized Measure of Discounted Future Net Cash Flows and Changes Therein Relating to Proved Oil and Gas Reserves

        Future cash inflowsare computed by applying year-end prices of oil and natural gas relating to Marathon’sMarathon's proved reserves to the year-end quantities of those reserves. Future price changes are considered only to the extent provided by contractual arrangements in existence at year-end.

                The assumptions used to compute the proved reserve valuation do not necessarily reflect Marathon’sMarathon's expectations of actual revenues to be derived from those reserves or their present worth. Assigning monetary values to the estimated quantities of reserves, described on the preceding page, does not reduce the subjective and ever-changing nature of such reserve estimates.

                Additional subjectivity occurs when determining present values because the rate of producing the reserves must be estimated. In addition to uncertainties inherent in predicting the future, variations from the expected production rate also could result directly or indirectly from factors outside of Marathon’sMarathon's control, such as unintentional delays in development, environmental concerns, changes in prices or regulatory controls.

                The reserve valuation assumes that all reserves will be disposed of by production. However, if reserves are sold in place or subjected to participation by foreign governments, additional economic considerations could also could affect the amount of cash eventually realized.

        Future development and production, transportation and administrative costs and development costs are computed by estimating the expenditures to be incurred in developing and producing the proved oil and gas reserves at the end of the year, based on year-end costs and assuming continuation of existing economic conditions.

        Future income tax expensesare computed by applying the appropriate year-end statutory tax rates, with consideration of future tax rates already legislated, to the future pretax net cash flows relating to Marathon’sMarathon's proved oil and gas reserves. Oil and gas related tax credits and allowances are recognized.

        Discountwas derived by using a discount rate of 10 percent annually.

                              
          United     Other  
        (In millions)December 31     States Europe Africa Int’l Total
         
        2005
                            
         Future cash inflows $17,346  $10,007  $18,088  $1,415  $46,856 
         Future production, transportation and administrative costs  (5,046)  (2,007)  (1,910)  (1,010)  (9,973)
         Future development costs  (853)  (1,531)  (751)  (61)  (3,196)
         Future income tax expenses  (3,738)  (3,199)  (9,687)  (55)  (16,679)
                        
         Future net cash flows $7,709  $3,270  $5,740  $289  $17,008 
         10 percent annual discount for estimated timing of cash flows  (2,862)  (829)  (2,427)  (73)  (6,191)
                        
         Standardized measure of discounted future net cash flows relating to proved oil and gas reserves $4,847  $2,441  $3,313  $216  $10,817 
         
        2004                    
         Future cash inflows $12,377  $7,742  $5,709  $750  $26,578 
         Future production, transportation and administrative costs  (4,337)  (1,950)  (951)  (565)  (7,803)
         Future development costs  (585)  (1,801)  (294)  (82)  (2,762)
         Future income tax expenses  (2,581)  (1,753)  (1,265)  (16)  (5,615)
                        
         Future net cash flows $4,874  $2,238  $3,199  $87  $10,398 
         10 percent annual discount for estimated timing of cash flows  (1,740)  (737)  (1,419)  (33)  (3,929)
                        
         Standardized measure of discounted future net cash flows relating to proved oil and gas reserves $3,134  $1,501  $1,780  $54  $6,469 
         
        2003                    
         Future cash inflows $13,331  $3,955  $4,471  $1,593  $23,350 
         Future production, transportation and administrative costs  (4,919)  (1,050)  (1,161)  (827)  (7,957)
         Future development costs  (758)  (435)  (175)  (229)  (1,597)
         Future income tax expenses  (2,612)  (870)  (780)  (163)  (4,425)
                        
         Future net cash flows  5,042   1,600   2,355   374   9,371 
         10 percent annual discount for estimated timing of cash flows  (1,789)  (301)  (1,112)  (168)  (3,370)
                        
         
        Standardized measure of discounted future net cash flows relating to proved oil and gas reserves(a)
         $3,253  $1,299  $1,243  $206  $6,001 
         Share of equity method investee’s standardized measure of discounted future net cash flow $–   $–   $–   $8  $8 
         
        (a)Excludes $(26) million of discounted future net cash flows from the effects of hedging transactions for 2003.

        (In millions)                                                              December 31
         United
        States

         Europe
         Africa
         Total
         

         
        2006             
         Future cash inflows $13,435 $8,713 $22,799 $44,947 
         Future production, transportation and administrative costs  (5,512) (2,564) (1,877) (9,953)
         Future development costs  (762) (1,781) (495) (3,038)
         Future income tax expenses  (2,217) (1,709) (14,847) (18,773)
          
         
         
         
         
         Future net cash flows $4,944 $2,659 $5,580 $13,183 
         10 percent annual discount for estimated timing of cash flows  (1,818) (408) (2,439) (4,665)
          
         
         
         
         
         Standardized measure of discounted future net cash flows relating to proved oil and gas reserves $3,126 $2,251 $3,141 $8,518 

         
        2005             
         Future cash inflows $17,346 $10,007 $18,088 $45,441 
         Future production, transportation and administrative costs  (5,046) (2,007) (1,910) (8,963)
         Future development costs  (853) (1,531) (751) (3,135)
         Future income tax expenses  (3,738) (3,199) (9,687) (16,624)
          
         
         
         
         
         Future net cash flows $7,709 $3,270 $5,740 $16,719 
         10 percent annual discount for estimated timing of cash flows  (2,862) (829) (2,427) (6,118)
          
         
         
         
         
         Standardized measure of discounted future net cash flows relating to proved oil and gas reserves $4,847 $2,441 $3,313 $10,601 
         Standardized measure of discounted future net cash flows relating to discontinued operations          $216 

         
        2004             
         Future cash inflows $12,377 $7,742 $5,709 $25,828 
         Future production, transportation and administrative costs  (4,337) (1,950) (951) (7,238)
         Future development costs  (585) (1,801) (294) (2,680)
         Future income tax expenses  (2,581) (1,753) (1,265) (5,599)
          
         
         
         
         
         Future net cash flows $4,874 $2,238 $3,199 $10,311 
         10 percent annual discount for estimated timing of cash flows  (1,740) (737) (1,419) (3,896)
          
         
         
         
         
         Standardized measure of discounted future net cash flows relating to proved oil and gas reserves(a) $3,134 $1,501 $1,780 $6,415 
         Standardized measure of discounted future net cash flows relating to discontinued operations          $54 

         

        F-48


        Supplementary Information on Oil and Gas Producing Activities (Unaudited)CONTINUED
        Summary of Changes in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves
                     
        (In millions) 2005 2004 2003
         
        Sales and transfers of oil and gas produced, net of production, transportation, and administrative costs $(3,868) $(2,715) $(2,487)
        Net changes in prices and production, transportation and administrative costs related to future production  6,783   950   1,178 
        Extensions, discoveries and improved recovery, less related costs  790   1,352   618 
        Development costs incurred during the period  1,115   711   802 
        Changes in estimated future development costs  (600)  (556)  (478)
        Revisions of previous quantity estimates  837   494   348 
        Net changes in purchases and sales of minerals in place  4,556   33   (531)
        Net change in exchanges of minerals in place  –    –    403 
        Accretion of discount  1,130   790   807 
        Net change in income taxes  (6,723)  (529)  65 
        Timing and other  328   (62)  (165)
         
        Net change for the year  4,348   468   560 
        Beginning of year  6,469   6,001   5,441 
         
        End of year $10,817  $6,469  $6,001 
        Net change for the year from discontinued operations $–   $–   $(384)
         

        (In millions)

         2006
         2005
         2004
         

         
        Sales and transfers of oil and gas produced, net of production, transportation and administrative costs $(5,312)$(3,754)$(2,689)
        Net changes in prices and production, transportation and administrative costs related to future production  (1,342) 6,648  771 
        Extensions, discoveries and improved recovery, less related costs  1,290  700  1,349 
        Development costs incurred during the period  1,251  1,030  609 
        Changes in estimated future development costs  (527) (552) (628)
        Revisions of previous quantity estimates  1,319  820  948 
        Net changes in purchases and sales of minerals in place  30  4,557  33 
        Accretion of discount  1,882  1,124  757 
        Net change in income taxes  (660) (6,694) (627)
        Timing and other  (14) 307  97 

         
        Net change for the year  (2,083) 4,186  620 
        Beginning of year  10,601  6,415  5,795 

         
        End of year $8,518 $10,601 $6,415 
        Net change for the year from discontinued operations $(216)$162 $(152)

         

        F-49


        Five-Year Operating Summary
                                  
          2005 2004 2003 2002 2001
         
        Net Liquid Hydrocarbon Sales(thousands of barrels per day)(a)
                            
         United States (by business unit)                    
          Northern  25   25   26   28   29 
          Southern  51   56   81   89   98 
                        
           Total United States  76   81   107   117   127 
                        
         International                    
          Australia  –    –    1   1   –  
          Equatorial Guinea  40   19   12   8   –  
          Gabon  12   13   15   17   16 
          Norway  2   2   1   1   –  
          United Kingdom  34   38   40   51   46 
          Russian Federation  27   16   9   –    –  
                        
           Total International  115   88   78   78   62 
                        
            Consolidated  191   169   185   195   189 
         Equity method investee  –    1   6   8   9 
                        
             Total Continuing Operations  191   170   191   203   198 
             Discontinued Operations  –    –    3   4   11 
                        
             Worldwide Total  191   170   194   207   209 
        Natural gas liquids included in above  18   15   18   20   19 
         
        Net Natural Gas Sales(millions of cubic feet per day)(a)
                            
         United States (by business unit)                    
          Northern  351   367   392   405   397 
          Southern  227   264   340   340   396 
                        
           Total United States  578   631   732   745   793 
                        
         International                    
          Equatorial Guinea  92   76   66   53   –  
          Ireland  50   58   62   81   79 
          Norway  34   27   16   15   5 
          United Kingdom – equity  140   188   184   203   234 
                                    – other(b)
          38   19   23   4   8 
                        
           Total International  354   368   351   356   326 
                        
            Consolidated  932   999   1,083   1,101   1,119 
         Equity method investee  –    –    13   25   31 
                        
             Total Continuing Operations  932   999   1,096   1,126   1,150 
             Discontinued Operations  –    –    74   104   123 
                        
             Worldwide Total  932   999   1,170   1,230   1,273 
         
        Average Sales Prices(excluding derivative gains and losses)
                            
         Liquid Hydrocarbons (dollars per barrel)                    
          United States $45.41  $32.76  $26.92  $22.18  $20.62 
          International  45.43   33.82   26.45   23.86   23.74 
           Consolidated  45.42   33.31   26.72   22.86   21.65 
          Equity method investee  –    21.10   25.91   24.59   23.41 
             Total Continuing Operations  45.42   33.24   26.70   22.93   21.73 
             Discontinued Operations  –    –    28.96   23.29   21.26 
             Worldwide  45.42   33.24   26.73   22.94   21.71 
         Natural Gas (dollars per thousand cubic feet)                    
          United States $6.42  $4.89  $4.53  $2.87  $3.69 
          International  4.28   3.33   2.77   2.30   2.78 
           Consolidated  5.61   4.31   3.96   2.69   3.42 
          Equity method investee  –    –    3.70   3.05   3.39 
             Total Continuing Operations  5.61   4.31   3.95   2.70   3.42 
             Discontinued Operations  –    –    5.43   3.30   4.17 
             Worldwide  5.61   4.31   4.05   2.75   3.49 
         
        Net Proved Reserves at year-end(developed and undeveloped)
                            
         Liquid Hydrocarbons (millions of barrels)                    
          United States  189   191   210   245   268 
          International  515   369   366   292   118 
                        
           Consolidated  704   560   576   537   386 
          Equity method investee  –    –    2   183   184 
                        
             Total  704   560   578   720   570 
         Developed reserves as a percentage of total net reserves  86%  69%  68%  82%  90%
         
         Natural Gas (billions of cubic feet)                    
          United States  1,209   1,364   1,635   1,724   1,793 
          International  2,338   2,108   1,149   1,594   1,014 
                        
           Consolidated  3,547   3,472   2,784   3,318   2,807 
          Equity method investee  –    –    –    59   51 
                        
             Total  3,547   3,472   2,784   3,377   2,858 
         Developed reserves as a percentage of total net reserves  54%  56%  72%  74%  74%
         
        (a)Amounts represent net sales after royalties, except for the U.K., Ireland and the Netherlands where amounts are shown before royalties for the applicable periods.
        (b)Represents gas acquired for injection and subsequent resale. Effective July 1, 2005, the methodology for allocating sales volumes between gas produced from the Brae complex and third-party gas production was modified, resulting in an increase in volumes representing gas acquired for injection and subsequent resale.


        Supplemental Statistics (Unaudited)

         
         2006
         2005
         2004
         

         
        Net Liquid Hydrocarbon Sales(thousands of barrels per day)(a)          
         United States  76  76  81 
         
        Europe

         

         

        35

         

         

        36

         

         

        40

         
         Africa  112  52  32 
          
         
         
         
           Total International  147  88  72 
          
         
         
         
            Worldwide Continuing Operations  223  164  153 
            Discontinued Operations  12  27  17 
          
         
         
         
            Worldwide  235  191  170 
         Natural gas liquids included in above  23  18  15 

         
        Net Natural Gas Sales(millions of cubic feet per day)(a)(b)          
         United States  532  578  631 
         
        Europe

         

         

        243

         

         

        262

         

         

        292

         
         Africa  72  92  76 
          
         
         
         
           Total International  315  354  368 
          
         
         
         
            Worldwide  847  932  999 

         
        Total Worldwide Sales(thousands of barrels of oil equivalent per day)          
         Continuing Operations  365  319  320 
         Discontinued Operations  12  27  17 
          
         
         
         
            Worldwide  377  346  337 

         
        Average Realizations(c)          
         Liquid Hydrocarbons (dollars per barrel)          
          United States $54.41 $45.41 $32.76 
          
        Europe

         

         

        64.02

         

         

        52.99

         

         

        37.16

         
          Africa  59.83  46.27  35.11 
            Total International  60.81  49.04  36.24 
            Worldwide Continuing Operations  58.63  47.35  34.40 
            Discontinued Operations  38.38  33.47  22.65 
            Worldwide $57.58 $45.42 $33.31 
         Natural Gas (dollars per thousand cubic feet)          
          United States $5.76 $6.42 $4.89 
          
        Europe

         

         

        6.74

         

         

        5.70

         

         

        4.13

         
          Africa  0.27  0.25  0.25 
            Total International  5.27  4.28  3.33 
              Worldwide $5.58 $5.61 $4.31 

         
        Net Proved Reserves at year-end(developed and undeveloped)          
         Liquid Hydrocarbons (millions of barrels)          
          United States  172  189  191 
          International  505  515  369 
          
         
         
         
            Total  677  704  560 
         Developed reserves as a percentage of total net reserves  84% 86% 69%

         
         Natural Gas (billions of cubic feet)          
          United States  1,069  1,209  1,364 
          International  2,441  2,338  2,108 
          
         
         
         
            Total  3,510  3,547  3,472 
         Developed reserves as a percentage of total net reserves  50% 54% 56%

         
        (a)
        Amounts represent net sales after royalties, except for Ireland where amounts are before royalties.
        (b)
        Includes natural gas acquired for injection and subsequent resale of 46 mmcfd, 38 mmcfd and 19 mmcfd in 2006, 2005 and 2004. Effective July 1, 2005, the methodology for allocating sales volumes between natural gas produced from the Brae complex and third-party natural gas production was modified, resulting in an increase in volumes representing natural gas acquired for injection and subsequent resale.
        (c)
        Excludes gains and losses on traditional derivative instruments and the unrealized effects of long-term U.K. natural gas contracts that are accounted for as derivatives.

        F-50


        (Dollars in millions, except as noted)

         2006
         2005
         2004
         

         
        Segment Income (Loss)          
        Exploration and Production          
         United States $873 $983 $674 
         International  1,130  904  416 
          
         
         
         
          E&P segment  2,003  1,887  1,090 
        Refining, Marketing and Transportation(a)  2,795  1,628  568 
        Integrated Gas  16  55  37 
          
         
         
         
          Segment income  4,814  3,570  1,695 
        Items not allocated to segments, net of income taxes:          
         Corporate and other unallocated items  (212) (377) (327)
         Gain (loss) on long-term U.K. natural gas contracts  232  (223) (57)
         Discontinued operations  277  45  (33)
         Gain on disposition of Syria interest  31  –    –   
         Deferred income taxes – tax legislation changes  21  15  –   
                                                     – other adjustments(b)  93  –    –   
         Loss on early extinguishment of debt  (22) –    –   
         Gain on sale of minority interests in EG Holdings  –    21  –   
         Corporate insurance adjustment  –    –    (17)
         Cumulative effect of change in accounting principle  –    (19) –   
          
         
         
         
         Net income $5,234 $3,032 $1,261 
         Net income per common share – basic (in dollars) $14.62 $8.52 $3.75 
                                                                     – diluted (in dollars) $14.50 $8.44 $3.73 

         
        Capital expenditures          
         Exploration and Production $2,169 $1,366 $840 
         Refining, Marketing and Transportation(a)  916  841  794 
         Integrated Gas(c)  307  571  488 
         Discontinued Operations  45  94  106 
         Corporate  41  18  19 
          
         
         
         
          Total $3,478 $2,890 $2,247 

         
        Exploration Expense          
         United States $169 $118 $78 
         International  196  99  80 
          Total $365 $217 $158 

         
        Refinery Runs(thousands of barrels per day)          
         Crude oil refined  980  973  939 
         Other charge and blend stocks  234  205  171 
          
         
         
         
           Total  1,214  1,178  1,110 

         
        Refined Product Yields(thousands of barrels per day)          
         Gasoline  661  644  608 
         Distillates  323  318  299 
         Propane  23  21  22 
         Feedstocks and special products  107  96  94 
         Heavy fuel oil  26  28  25 
         Asphalt  89  85  77 
          
         
         
         
           Total  1,229  1,192  1,125 

         
        Refined Product Sales Volumes(thousands of barrels per day)(d)(e)  1,425  1,455  1,400 
         Matching buy/sell volumes included in above(e)  24  77  71��

         
        Refining and Wholesale Marketing Gross Margin($ per gallon)(f) $0.2288 $0.1582 $0.0877 

         
        Speedway SuperAmerica          
         Retail outlets at year-end  1,636  1,638  1,669 
         Gasoline & distillates sales (millions of gallons)  3,301  3,226  3,152 
         Gasoline & distillates gross margin (dollars per gallon) $0.1156 $0.1230 $0.1186 
         Merchandise sales $2,706 $2,531 $2,335 
         Merchandise gross margin $667 $626 $571 

         
        (a)
        RM&T segment income for 2005 and 2004 is net of $376 million and $539 million pretax minority interest in MPC. RM&T capital expenditures include MPC at 100 percent for all periods.
        (b)
        Other deferred tax adjustments in 2006 represent a benefit recorded for cumulative income tax basis differences associated with prior periods.
        (c)
        Includes Equatorial Guinea LNG Holdings at 100 percent.
        (d)
        Total average daily volumes of refined product sales to wholesale, branded and retail (SSA) customers.
        (e)
        As a result of the change in accounting for matching buy/sell arrangements on April 1, 2006, the reported sales volumes will be lower than the volumes determined under the previous accounting practices. See Note 2 to the consolidated financial statements.
        (f)
        Sales revenue less cost of refinery inputs, purchased products and manufacturing expenses, including depreciation. As a result of the change in accounting for matching buy/sell transactions on April 1, 2006, the resulting per gallon statistic will be higher than the statistic that would have been calculated from amounts determined under previous accounting practices. See Note 2 to the consolidated financial statements.

        F-51


        Five-Year Operating SummaryCONTINUED
                                 
          2005(a) 2004(a) 2003(a) 2002(a) 2001(a)
         
        Refinery Operations(thousands of barrels per day)
                            
         In-use crude oil capacity at year-end  974   948   935   935   935 
         Refinery runs– crude oil refined  973   939   917   906   929 
            – other charge and blend stocks  205   171   138   148   143 
         In-use crude oil capacity utilization rate  102%  99%  98%  97%  99%
         
        Source of Crude Processed(thousands of barrels per day)
                            
         United States  447   416   422   433   403 
         Canada  111   130   122   114   115 
         Middle East and Africa  301   276   266   232   347 
         Other International  114   117   107   127   64 
                        
          Total  973   939   917   906   929 
         
        Refined Product Yields(thousands of barrels per day)
                            
         Gasoline  644   608   567   581   581 
         Distillates  318   299   284   285   286 
         Propane  21   22   21   21   22 
         Feedstocks and special products  96   94   93   80   69 
         Heavy fuel oil  28   25   24   20   39 
         Asphalt  85   77   72   72   76 
                        
          Total  1,192   1,125   1,061   1,059   1,073 
         
        Refined Product Sales Volumes(thousands of barrels per day)(b)
                            
         Gasoline  836   807   776   773   748 
         Distillates  385   373   365   346   345 
         Propane  22   22   21   22   21 
         Feedstocks and special products  96   92   97   82   71 
         Heavy fuel oil  29   27   24   20   41 
         Asphalt  87   79   74   75   78 
                        
          Total  1,455   1,400   1,357   1,318   1,304 
         Matching buy/sell volumes included in above  77   71   64   71   45 
         
        Refined Products Sales Volumes by Class of Trade(as a % of total)
                            
         Wholesale & spot market – independent private-brand marketers and consumers 72%  72%  71%  69%  66%
         Marathon brand jobbers and dealers  13%  13%  13%  13%  13%
         Speedway SuperAmerica retail outlets  15%  15%  16%  18%  21%
          Total  100%  100%  100%  100%  100%
         
        Refined Products(dollars per barrel)
                            
         Average sales price $66.42  $49.53  $38.55  $32.26  $34.54 
         Average cost of crude oil throughput $51.85  $39.16  $29.77  $25.41  $23.47 
         
        Refining and Wholesale Marketing Margin(dollars per gallon)(c)
         $0.1582  $0.0877  $0.0603  $0.0387  $0.1167 
         
        Refined Product Marketing Outlets at year-end
                            
         MPC operated terminals  85   84   88   86   87 
         Retail– Marathon brand  4,003   3,912   3,885   3,822   3,800 
           – Speedway SuperAmerica  1,638   1,669   1,775   2,006   2,104 
         
        Speedway SuperAmerica
                            
         Gasoline & distillates sales (millions of gallons)  3,226   3,152   3,332   3,604   3,572 
         Gasoline & distillates gross margin (dollars per gallon) $0.1230  $0.1186  $0.1229  $0.1007  $0.1206 
         Merchandise sales (millions) $2,531  $2,335  $2,244  $2,380  $2,253 
         Merchandise gross margin (millions) $626  $571  $555  $576  $527 
         
        Petroleum Inventories at year-end(thousands of barrels)
                            
         Crude oil, raw materials and natural gas liquids  32,343   31,577   31,862   32,600   32,741 
         Refined products  39,925   38,653   37,650   37,729   36,310 
         
        Pipelines(miles of common carrier pipelines)(d)
                            
         Crude Oil– gathering lines  68   68   68   200   271 
            – trunklines  3,806   3,893   4,105   4,459   4,511 
         Products– trunklines  3,824   3,850   3,861   3,732   2,847 
          Total  7,698   7,811   8,034   8,391   7,629 
         
        Pipeline Barrels Handled(in millions)(e)
                            
         Crude Oil– gathering lines  6.6   6.8   12.7   14.1   16.3 
            – trunklines  597.8   577.9   583.3   575.7   570.6 
         Products– trunklines  444.7   406.8   371.3   367.6   345.6 
          Total  1,049.1   991.5   967.3   957.4   932.5 
         
        River Operations
                            
         Barges– owned/leased  173   167   155   150   156 
         Boats– owned/leased  10   9   7   7   8 
         
        (a)Statistics include 100 percent of MPC.
        (b)Total average daily volumes of refined product sales to wholesale, branded and retail (SSA) customers.
        (c)Sales revenue less cost of refinery inputs, purchased products and manufacturing expenses, including depreciation.
        (d)Pipelines for downstream operations also include non-common carrier, leased and equity method investees.
        (e)Pipeline barrels handled on owned common carrier pipelines, excluding equity method investees.

        F-51
        Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure


                None.


        Item 9A. Controls and Procedures

        Five-Year Selected Financial Data
                                
        (Dollars in millions, except as noted) 2005 2004 2003 2002 2001
         
        Revenues and Other Income
                            
         Revenues by product:                    
          Refined products $40,040  $29,780  $24,092  $19,729  $20,841 
          Merchandise  2,689   2,489   2,395   2,521   2,506 
          Liquid hydrocarbons  16,677   13,860   10,500   6,517   6,502 
          Natural gas  3,675   3,266   3,796   2,362   2,801 
          Transportation and other products  230   203   180   166   146 
                        
           Total revenues  63,311   49,598   40,963   31,295   32,796 
         Gain (loss) on ownership change in MPC  –    2   (1)  12   (6)
         
        Other(a)
          362   307   272   248   272 
                        
           Total revenues and other income $63,673  $49,907  $41,234  $31,555  $33,062 
         
        Income From Operations
                            
         Exploration and production                    
          Domestic $1,564  $1,073  $1,155  $726  $1,150 
          International  1,424   623   425   333   229 
                        
           E&P segment income  2,988   1,696   1,580   1,059   1,379 
         Refining, marketing and transportation  3,013   1,406   819   372   1,927 
         Integrated gas  31   48   (3)  23   21 
                        
           Segment income  6,032   3,150   2,396   1,454   3,327 
         Items not allocated to segments:                    
          Administrative expenses  (367)  (307)  (227)  (194)  (187)
          Gain on disposal of assets  –    –    106   24   –  
          Inventory market valuation adjustments  –    –    –    71   (71)
          Impairment of certain oil and gas properties  –    (44)  –    –    –  
          Loss on dissolution of MKM Partners LLP  –    –    (124)  –    –  
          Gain (loss) on U.K. long-term gas contracts  (386)  (99)  (66)  18   –  
          Other items  23   (30)  (1)  (3)  39 
                        
           Income from operations  5,302   2,670   2,084   1,370   3,108 
         Minority interest in income of MPC  384   532   302   173   704 
         Minority interest in loss of EGHoldings  (8)  (7)  –    –    –  
         Net interest and other financing costs  145   161   186   321   172 
         Provision for income taxes  1,730   727   584   369   827 
                        
        Income From Continuing Operations
         $3,051  $1,257  $1,012  $507  $1,405 
         Per common share – basic (in dollars) $8.57  $3.74  $3.26  $1.63  $4.54 
          – diluted (in dollars) $8.49  $3.72  $3.26  $1.63  $4.54 
        Net Income
         $3,032  $1,261  $1,321  $516  $377 
         Per common share – basic (in dollars) $8.52  $3.75  $4.26  $1.66  $1.22 
          – diluted (in dollars) $8.44  $3.73  $4.26  $1.66  $1.22 
         
        Balance Sheet Position at year-end
                            
         Current assets $9,383  $8,866  $6,040  $4,479  $4,411 
         Net property, plant and equipment  15,011   11,810   10,830   10,390   9,552 
         Total assets  28,498   23,423   19,482   17,812   16,129 
         Short-term debt  315   16   272   161   215 
         Other current liabilities  7,839   5,237   3,935   3,498   3,253 
         Long-term debt  3,698   4,057   4,085   4,410   3,432 
         Minority interest in subsidiaries  435   2,690   2,011   1,971   1,963 
         Common stockholders’ equity  11,705   8,111   6,075   5,082   4,940 
         
        Cash Flow Data – Continuing Operations
                            
         Net cash from operating activities $4,738  $3,766  $2,682  $2,331  $2,749 
         Capital expenditures  2,890   2,247   1,909   1,520   1,533 
         Disposal of assets  131   76   644   146   83 
         Dividends paid  436   348   298   285   284 
         Dividends paid per share  1.22   1.03   0.96   0.92   0.92 
         
        Employee Data
                            
         Marathon:                    
          Total employment costs $1,746  $1,672  $1,560  $1,481  $1,498 
          Average number of employees  26,916   26,580   27,677   28,237   30,791 
          Number of pensioners at year-end  3,029   3,117   3,291   3,122   3,105 
         Speedway SuperAmerica LLC (included in Marathon totals):                    
          Total employment costs $453  $446  $464  $480  $496 
          Average number of employees  17,514   17,077   17,911   18,943   21,449 
          Number of pensioners at year-end  223   245   234   214   205 
         
        Stockholder Data at year-end
                            
         Number of common shares outstanding (in millions)  366.7   346.7   310.4   309.9   309.4 
         Registered shareholders (in thousands)  69.2   58.6   61.9   66.4   69.7 
         Market price of common stock $60.97  $37.61  $33.09  $21.29  $30.00 
         
        (a)Includes income from equity method investments, net gains (losses) on disposal of assets and other income.

        F-52


        Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure
              None.
        Item 9A. Controls and Procedures
        Disclosure Controls and Procedures

                An evaluation of the effectiveness of the design and operation of our disclosure controls and procedures (as defined in Rules 13(a)-15(e) and15(d)-15(e) under the Securities and Exchange Act of 1934) was carried out under the supervision and with the participation of Marathon’sMarathon's management, including our Chief Executive Officer and Chief Financial Officer. As of the end of the period covered by this report based upon that evaluation, the Chief Executive Officer and Chief Financial Officer concluded that the design and operation of these disclosure controls and procedures were effective, and thateffective. During the period covered by this report, there were no significant changes in our internal controls over financial reporting that have materially affected, or in other factors that could significantlywere reasonably likely to materially affect, our internal controls subsequent to the date of their evaluation.

        over financial reporting.

        Internal Controls

                See “Management’s"Management's Report on Internal Control over Financial Reporting”Reporting" on page F-2.

        F-2.

        Item 9B. Other Information

        Item 9B. Other Information

                None.


        PART III

        Item 10. Directors and Executive Officers of the Registrant
        Item 10. Directors, Executive Officers and Corporate Governance

                Information concerning the directors of Marathon required by this item is incorporated by reference to the material appearing under the heading ”Election"Election of Directors”Directors" in Marathon’sMarathon's Proxy Statement for the 20062007 Annual Meeting of stockholders.

             Marathon’s

                Marathon's Board of Directors has established the Audit Committee and determined our “Audit"Audit Committee Financial Expert." The information required to be disclosed is incorporated by reference to the material appearing under the sub-heading “Audit Committee”"Audit Committee" located under the heading “The"The Board of Directors and Governance Matters”Matters" in Marathon’sMarathon's Proxy Statement for the 20062007 Annual Meeting of Stockholders.

                Marathon has adopted a Code of Ethics for Senior Financial Officers. It is available on our website at www.marathon.com/Code  Ethics  Sr  Finan  Off/.

        Executive Officers of the Registrant

                The executive officers of Marathon or its subsidiaries and their ages as of February 1, 2006,2007, are as follows:

        Albert G. Adkins58Vice President, Accounting
        Philip G. Behrman 5556 Senior Vice President, Worldwide Exploration
        Clarence P. Cazalot, Jr. 5556 President and Chief Executive Officer, and Director
        Janet F. Clark 5152 SeniorExecutive Vice President and Chief Financial Officer
        Gary R. Heminger 5253 Executive Vice President
        Steven B. Hinchman 4748 Senior Vice President, Worldwide Production
        Jerry Howard 5758 Senior Vice President, Corporate Affairs
        Alard Kaplan 5556 Vice President, Major Projects
        Kenneth L. Matheny 5859 Vice President, Investor Relations and Public Affairs
        Paul C. Reinbolt 5051 Vice President, Finance and Treasurer
        David E. Roberts46Senior Vice President, Business Development
        William F. Schwind, Jr. 6162 Vice President, General Counsel and Secretary
        Michael K. Stewart49Vice President, Accounting and Controller

        61


                With the exception of Ms. Clark, Mr. Kaplan and Mr. Kaplan,Roberts, all of the executive officers have held responsible management or professional positions with Marathon or its subsidiaries for more than the past five years.

                Ms. Clark joined Marathon in January 2004 as senior vice president and chief financial officer. Prior to joining Marathon, she was employed by Nuevo Energy Company from 2001 to December 2003 as senior vice president and chief financial officer.

        58


                Mr. Kaplan joined Marathon in December 2003 as vice president, major projects. Prior to joining Marathon, he was employed by Foster Wheeler Corporation since 2001, with his most recent position as director of LNG for Foster Wheeler’sWheeler's Houston office.

                Mr. Roberts joined Marathon in June 2006 as senior vice president, business development. Prior to joining Marathon, he was employed by BG Group from 2003 as executive vice president/managing director responsible for Asia and the Middle East. He served as advisor to the vice chairman of ChevronTexaco Corporation from 2001 to 2003.

        Section 16(a) Beneficial Ownership Reporting Compliance

                Section 16(a) of the Securities and Exchange Act of 1934, as amended, requires that the Company’sCompany's directors and executive officers, and persons who own more than ten percent of a registered class of the Company’sCompany's equity securities, file reports of beneficial ownership on Form 3 and changes in beneficial ownership on Form 4 or Form 5 with the Securities and Exchange Commission. Based solely on the Company’sCompany's review of the reporting forms and written representations provided to the Company from the individuals required to file reports, the Company believes that each of its executive officers and directors has complied with the applicable reporting requirements for transactions in the Company’sCompany's securities during the fiscal year ended December 31, 2005.

        2006, except for Michael K. Stewart who filed one Form 4 report two days late relating to shares-for-tax withholding for a vesting of restricted stock granted to Mr. Stewart prior to his election as an executive officer of the Company.


        Item 11. Executive Compensation

                Information required by this item is incorporated by reference to the material appearing under the heading “Executive"Executive Compensation Tables and Other Information”Information;" under the sub-headings "Compensation Committee" and "Compensation Committee Interlocks and Insider Participation" under the heading "The Board of Directors and Governance Matters;" and under the heading "Compensation Committee Report" in Marathon’sMarathon's Proxy Statement for the 20062007 Annual Meeting of stockholders.

        Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

        Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

                Information required by this item is incorporated by reference to the material appearing under the headings “Security"Security Ownership of Certain Beneficial Owners”Owners" and “Security"Security Ownership of Directors and Executive Officers”Officers" in Marathon’sMarathon's Proxy Statement for the 20062007 Annual Meeting of stockholders.

        Equity Compensation Plan Information
              The following table provides information as of December 31, 2005, with respect to shares of Marathon’s common stock that may be issued under Marathon’s existing equity compensation plans:
        • 2003 Incentive Compensation Plan
        • 1990 Stock Plan – No additional awards will be granted under this plan.
        • Deferred Compensation Plan for Non-Employee Directors – No additional awards will be granted under this plan.
        • 2001 Non-Officer Restricted Stock Plan – No additional awards will be granted under this plan.
                     
          (a) (b) (c)
               
              Number of securities remaining
          Number of securities to Weighted-average available for future issuance
          be issued upon exercise exercise price of under equity compensation
          of outstanding options, outstanding options, plans (excluding securities
        Plan category warrants and rights warrants and rights reflected in column (a))
         
        Equity compensation plans approved by stockholders  6,590,421(a) $36.50   12,871,252(b)
        Equity compensation plans not approved by stockholders(c)
          89,363(d)  N/A   –  
        Total  6,679,784(a) $36.50   12,871,252(b)
         
        (a)This number includes the following:
        • 4,851,892 stock options and stock appreciation rights outstanding under the 2003 Incentive Compensation Plan (the “Incentive Plan”).
        • 1,107,762 stock options outstanding under the 1990 Stock Plan.
        • 448,600 performance shares granted to officers under the Incentive Plan but not yet earned as of December 31, 2005. The number of shares, if any, to be issued will be determined based on a formula that measures Marathon’s total shareholder return over the applicable performance period relative to the total shareholder return of its industry peers.
        • 48,249 phantom shares that have been credited to non-employee directors pursuant to the non-employee director deferred compensation program and the annual director stock award program established under the Incentive Plan. When a non-employee director leaves the Board, he or she will be issued actual shares of Marathon common stock in place of the phantom shares.
        • 133,918 restricted stock phantom units granted to non-officers under the Incentive Plan and outstanding as of December 31, 2005.
        The weighted-average exercise price shown in column (b) does not take the officer performance shares, the phantom shares or the restricted stock units into account since these awards have no exercise price.
        (b)This number reflects the shares available for issuance under the Incentive Plan. No more than 6,690,250 of these shares may be issued for awards other than stock options or stock appreciation rights. In addition, shares subject to awards that are forfeited, terminated, expire unexercised, or are settled in such manner that all or some of the shares are not issued to a participant shall immediately become available for future grants.

        59
        Item 13. Certain Relationships and Related Transactions, and Director Independence


        (c)This reflects awards made under the Deferred Compensation Plan for Non-Employee Directors and the 2001 Non-Officer Restricted Stock Plan prior to April 30, 2003.
        (d)This number includes the following:
        • 57,243 phantom shares that were awarded to non-employee directors under the Deferred Compensation Plan for Non-Employee Directors prior to April 30, 2003. When a non-employee director leaves the Board, he or she will be issued actual shares of Marathon common stock in place of the phantom shares.
        • 32,120 restricted stock phantom units granted under the 2001 Non-Officer Restricted Stock Plan and outstanding as of December 31, 2005.
        Equity Compensation Plans Not Approved by Stockholders
        Non-Officer Restricted Stock Plan –The Non-Officer Restricted Stock Plan was approved by the Board of Directors effective January 1, 2001, to provide restricted stock and restricted stock unit awards to non-officer employees of Marathon and its affiliates. The purposes of the plan are to reward specific noteworthy achievements by non-officer employees and promote the retention of outstanding non-officer employees. All awards under this plan are subject to a four-year time-based vesting schedule, with 50% of the shares vesting two years from the date of grant and the remaining 50% of the shares vesting four years from the date of grant. If a recipient terminates employment other than by reason of death, any unvested portion of his or her award will be forfeited. Dividends are paid on all awards made under the plan prior to vesting. Marathon’s authority to make grants under this plan was terminated effective as of April 30, 2003.
        Deferred Compensation Plan for Non-Employee Directors –Under the Deferred Compensation Plan for Non-Employee Directors, all non-employee directors of Marathon were required to defer half of their annual retainers in the form of common stock units. On the date the retainer would have otherwise been payable to the non-employee director, Marathon credited an unfunded bookkeeping account for each non-employee director with a number of common stock units equal to half of his or her annual retainer divided by the fair market value of Marathon’s common stock. The ongoing value of each common stock unit equals the market price of Marathon’s common stock. When dividends are paid, Marathon credits each unfunded account with dividend equivalents on the number of units then in the individual’s account in the form of additional common stock units. When the non-employee director leaves the Board, he or she is issued actual shares of common stock equal to the number of common stock units in his or her account at that time. Marathon’s authority to make equity grants under this plan was terminated effective as of April 30, 2003.
        Item 13. Certain Relationships and Related Transactions
                Information required by this item is incorporated by reference to the material appearing under the heading ”Certain"Certain Relationships and Related Party Transactions”Person Transactions," and under the sub-heading "Board and Committee Independence" under the heading "The Board of Directors and Governance Matters" in Marathon’sMarathon's Proxy Statement for the 20062007 Annual Meeting of stockholders.

        Item 14. Principal Accounting Fees and Services

        Item 14. Principal Accounting Fees and Services

                Information required by this item is incorporated by reference to the material appearing under the heading ”Information"Information Regarding the Independent Registered Public Accounting Firm’sFirm's Fees, Services and Independence”Independence" in Marathon’sMarathon's Proxy Statement for the 20062007 Annual Meeting of stockholders.

        6062



        PART IV

        Item 15. Exhibits and Financial Statement Schedules
        Item 15. Exhibits, Financial Statement Schedules

        A. Documents Filed as Part of the Report

        1. Financial Statements (see Part II, Item 8. of this report regarding financial statements)
        2. Financial Statement Schedules
        Financial Statement Schedules listed under SEC rules but not included in this report are omitted because they are not applicable or the required information is contained in the financial statements or notes thereto.
        Schedule II – Valuation and Qualifying Accounts is provided on page 66.

          1.
          Financial Statements (see Part II, Item 8. of this report regarding financial statements)

          2.
          Financial Statement Schedules

              Financial Statement Schedules listed under SEC rules but not included in this report are omitted because they are not applicable or the required information is contained in the financial statements or notes thereto.

          3.
          Exhibits:

        Any reference made to USX Corporation in the exhibit listing that follows is a reference to the former name of Marathon Oil Corporation, a Delaware corporation and the registrant, and is made because the exhibit being listed and incorporated by reference was originally filed before July, 2001, the date of the change in the registrant’sregistrant's name.

        References to Marathon Ashland Petroleum LLC or MAP are references to the entity now known as Marathon Petroleum Company LLC.

        Exhibit No.

        Description

        Exhibit
        2.

        No.Description
        2.
        Plan of Acquisition, Reorganization, Arrangement, Liquidation or Succession

        2.1*
        2.1

        Holding Company Reorganization Agreement, dated as of July 1, 2001, by and among USX Corporation, USX Holdco, Inc. and United States Steel LLC (incorporated by reference to Exhibit 2.1 to USX Corporation’s Form 8-K filed on July 2, 2001).LLC.

        2.2*
        2.2

        Agreement and Plan of Reorganization, dated as of July 31, 2001, by and between USX Corporation and United States Steel LLC (incorporated by reference to Exhibit 2.1 to the Registration Statement on Form S-4 (File No. 333-69090) of USX Corporation filed on September 7, 2001).LLC.

        2.3++
        2.3††

        Master Agreement, among Ashland Inc., ATB Holdings Inc., EXM LLC, New EXM Inc., Marathon Oil Corporation, Marathon Oil Company, Marathon Domestic LLC and Marathon Ashland Petroleum LLC, dated as of March 18, 2004 and Amendment No. 1 dated as of April 27, 2005 (incorporated by reference to Exhibit 2.1 on Amendment No. 3 to the Registration Statement on Form S-4/A (File No. 333-119694) of Marathon Oil Corporation filed on May 19, 2005).

        2.4++
        2.4††

        Amended and Restated Tax Matters Agreement among Ashland Inc., ATB Holdings Inc., EXM LLC, New EXM Inc., Marathon Oil Corporation, Marathon Oil Company, Marathon Domestic LLC and Marathon Ashland Petroleum LLC, dated as of April 27, 2005 (incorporated by reference to Exhibit 2.2 on Amendment No. 3 to the Registration Statement on Form S-4/A (File No. 333-119694) of Marathon Oil Corporation filed on May 19, 2005).

        2.5++
        2.5††

        Assignment and Assumption Agreement (VIOC Centers) between Ashland Inc. and ATB Holdings Inc., dated as of March 18, 2004 (incorporated by reference to Exhibit 2.3 to Marathon Oil Corporation’sCorporation's Amendment No. 1 to Form 8-K/A, filed on November 29, 2004).

        2.6++
        2.6††

        Assignment and Assumption Agreement (Maleic Business) between Ashland Inc. and ATB Holdings Inc., dated as of March 18, 2004 (incorporated by reference to Exhibit 2.4 to Marathon Oil Corporation’sCorporation's Amendment No. 1 to Form 8-K/A, filed on November 29, 2004).

        3.
        2.7††
        Amendment No. 2, dated as of March 18, 2004, and Amendment No. 3 dated as of April 27, 2005, to the Amended and Restated Limited Liability Company Agreement of Marathon Ashland Petroleum LLC (incorporated by reference to Exhibit 2.6 on Amendment No. 3 to the Registration Statement on Form S-4/A (File No. 333-119694) of Marathon Oil Corporation filed on May 19, 2005).
        3.
        Articles of Incorporation and Bylaws

        3.1*
        3.1

        Restated Certificate of Incorporation of Marathon Oil Corporation (incorporated by reference to Exhibit 3(a) to Marathon Oil Corporation’s Annual Report on Form 10-K for the year ended December 31, 2001).Corporation.

        3.2

         

        By-laws of Marathon Oil Corporation (incorporated by reference to Exhibit 3(b)3.1 to Marathon Oil Corporation’s Annual ReportCorporation's Form 8-K filed on Form 10-K for the year ended December 31, 2002)October 27, 2006).

        4.
        4.

        Instruments Defining the Rights of Security Holders, Including Indentures

        4.1

         

        Five Year Credit Agreement dated as of May 20, 2004 among Marathon Oil Corporation, the Co-Agents and other Lenders party thereto, Bank of America, N.A., as Syndication Agent, ABN Ambro Bank N.V., Citibank, N.A. and Morgan Stanley Bank, as Documentation Agents and JPMorgan Chase Bank, as Administrative Agent (incorporated by reference to Exhibit 4.1 to Marathon Oil Corporation’sCorporation's Form 10-Q for the quarter ended June 30, 2004).
         4.2 

        63



        4.2
        Five Year

        Amendment No. 1 dated as of May 4, 2006 to Five-Year Credit Agreement dated as of May 20, 2004 among Marathon Ashland Petroleum LLC,Oil Corporation, the Co-Agents and other Lenders party thereto, Bank of America, N.A., as Syndication Agent, ABN Ambro Bank N.V., Citibank,  N.A. and Morgan Stanley Bank, as Documentation Agents and JPMorgan Chase Bank, as Administrative Agent (incorporated by reference to Exhibit 4.24.1 to Marathon Oil Corporation’sCorporation's Form 10-Q for the quarter ended June 30, 2004).

        61


        Exhibit
        No.Description
          4.3Senior Indenture dated February 26, 2002 between Marathon Oil Corporation and JPMorgan Chase Bank, as Trustee (incorporated by reference to Exhibit 4.1 to Marathon Oil Corporation’s Form 8-K, filed on March 4, 2002)31, 2006).

         
          4.4
        Senior Indenture dated June 14, 2002 among Marathon Global Funding Corporation, Issuer, Marathon Oil Corporation, Guarantor, and JPMorgan Chase Bank, Trustee (incorporated by reference to Exhibit 4.1 to Marathon Oil Corporation’s Form 8-K, filed on June 21, 2002).
          4.5Senior Supplemental Indenture No. 1 dated as of September 5, 2003 among Marathon Global Funding Corporation, Issuer, Marathon Oil Corporation, Guarantor, and JPMorgan Chase Bank, Trustee to the Indenture dated as of June 14, 2002 (incorporated by reference to Exhibit 4.1 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2003).

        Pursuant to CFR 229.601(b)(4)(iii), instruments with respect to long-term debt issues have been omitted where the amount of securities authorized under such instruments does not exceed 10% of the total consolidated assets of Marathon. Marathon hereby agrees to furnish a copy of any such instrument to the Commission upon its request.

        10.
        10.

        Material Contracts

        10.1

         
        Amended and Restated Limited Liability Company Agreement of Marathon Ashland Petroleum LLC, dated as of December 31, 1998 (incorporated by reference to Exhibit 10.1 to Marathon Oil Corporation’s Amendment No. 1 to Form 8-K/A, filed on November 29, 2004).
        10.2Amendment No. 1 dated as of March 17, 2004, to the Amended and Restated Limited Liability Company Agreement of Marathon Ashland Petroleum LLC, dated as of December 31, 1998, by and between Marathon Oil Company and Ashland, Inc. (incorporated by reference to Exhibit 10.1 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2004).
        10.3
        Tax Sharing Agreement between USX Corporation and United States Steel LLC (converted into United States Steel Corporation) dated as of December 31, 2001 (incorporated by reference to Exhibit 99.3 to Marathon Oil Corporation’sCorporation's Form 8-K filed January 3, 2002).

        10.2
        10.4

        Financial Matters Agreement between USX Corporation and United States Steel LLC (converted into United States Steel Corporation) dated as of December 31, 2001 (incorporated by reference to Exhibit 99.5 to Marathon Oil Corporation’sCorporation's Form 8-K, filed on January 3, 2002).

        10.3
        10.5

        Insurance Assistance Agreement between USX Corporation and United States Steel LLC (converted into United States Steel Corporation) dated as of December 31, 2001 (incorporated by reference to Exhibit 99.6 to Marathon Oil Corporation’sCorporation's Form 8-K, filed on January 3, 2002).

        10.4
        10.6
        License Agreement between USX Corporation and United States Steel LLC (converted into United States Steel Corporation) dated as of December 31, 2001 (incorporated by reference to Exhibit 99.7 to Marathon Oil Corporation’s Form 8-K, filed on January 3, 2002).
        10.7
        Marathon Oil Corporation 2003 Incentive Compensation Plan, Effective January 1, 2003 (incorporated by reference to Appendix C to Marathon Oil Corporation’sCorporation's Definitive Proxy Statement on Schedule 14A filed on March 10, 2003).

        10.5*
        10.8

        Marathon Oil Corporation 1990 Stock Plan, as Amended and Restated Effective January 1, 2002 (incorporated by reference to Exhibit 10(a) to Marathon Oil Corporation’s Annual Report on Form 10-K for the year ended December 31, 2001).2002.

        10.6
        10.9

        Second Amended and Restated Marathon Oil Corporation Non-Officer Restricted Stock Plan, As Amended and Restated Effective January 2, 2002 (incorporated by reference to Exhibit 10.2 to Marathon Oil Corporation’sCorporation's Amendment No. 1 to Form 10-Q/A for the quarter ended September 30, 2002).

        10.7
        10.10

        Marathon Oil Corporation Deferred Compensation Plan for Non-Employee Directors (Amended and Restated as of January 1, 2002) (incorporated by reference to Exhibit 10.12 to Marathon Oil Corporation’sCorporation's Amendment No. 1 to Form 10-Q for the quarter ended September 30, 2002).

        10.8
        10.11

        First Amendment to the Marathon Oil Corporation Deferred Compensation Plan for Non-Employee Directors (Amended and Restated as of January 1, 2002) (incorporated by reference to Exhibit 10.1 to Marathon Oil Corporation’sCorporation's Form 8-K, filed on December 8, 2005).

        10.9
        10.12
        Form of Non-Qualified Stock Option Grant for Chief Executive Officer granted under
        Second Amendment to the Marathon Oil Corporation’s 1990 StockCorporation Deferred Compensation Plan as amended and restated effective January 1, 2002for Non-Employee Directors (incorporated by reference to Exhibit 10.210.1 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2004)Corporation's form 8-K filed on October 27, 2006).

        10.10
        10.13

        Form of Non-Qualified Stock Option Grant for Executive Officers granted under Marathon Oil Corporation’sCorporation's 1990 Stock Plan, as amended and restated effective January 1, 2002 (incorporated by reference to Exhibit 10.3 to Marathon Oil Corporation’sCorporation's Form 10-Q for the quarter ended September 30, 2004).

        10.11
        10.14*

        Form of Non-Qualified Stock Option Grant for MAP officers granted under Marathon Oil Corporation’sCorporation's 1990 Stock Plan, as amended and restated effective January 1, 2002.2002 (incorporated by reference to Exhibit 10.14 to Marathon Oil Corporation's Annual Report on Form 10-K for the year ended December 31, 2005).

        10.12
        10.15

        Form of Non-Qualified Stock Option with Tandem Stock Appreciation Right Award Agreement for Chief Executive Officer granted under Marathon Oil Corporation’sCorporation's 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.4 to Marathon Oil Corporation’sCorporation's Form 10-Q for the quarter ended September 30, 2004).

        62



        10.13

         
        Exhibit
        No.Description
        10.16
        Form of Non-Qualified Stock Option with Tandem Stock Appreciation Right Award Agreement for Executive Committee members granted under Marathon Oil Corporation’sCorporation's 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.5 to Marathon Oil Corporation’sCorporation's Form 10-Q for the quarter ended September 30, 2004).

        10.14
        10.17

        Form of Non-Qualified Stock Option with Tandem Stock Appreciation Right Award Agreement for Officers granted under Marathon Oil Corporation’sCorporation's 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.6 to Marathon Oil Corporation’sCorporation's Form 10-Q for the quarter ended September 30, 2004).
         10.18* 

        64



        10.15


        Form of Non-Qualified Stock Option Award Agreement for MAP officers granted under Marathon Oil Corporation’sCorporation's 2003 Incentive Compensation Plan, effective January 1, 2003.2003 (incorporated by reference to Exhibit 10.18 to Marathon Oil Corporation's Annual Report on Form 10-K for the year ended December 31, 2005).

        10.16
        10.19

        Form of Stock Appreciation Right Award Agreement for Chief Executive Officer granted under Marathon Oil Corporation’sCorporation's 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.7 to Marathon Oil Corporation’sCorporation's Form 10-Q for the quarter ended September 30, 2004).

        10.17
        10.20

        Form of Stock Appreciation Right Award Agreement for Executive Committee members granted under Marathon Oil Corporation’sCorporation's 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.8 to Marathon Oil Corporation’sCorporation's Form 10-Q for the quarter ended September 30, 2004).

        10.18
        10.21

        Form of Stock Appreciation Right Award Agreement for Officers granted under Marathon Oil Corporation’sCorporation's 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.9 to Marathon Oil Corporation’sCorporation's Form 10-Q for the quarter ended September 30, 2004).

        10.19
        10.22

        Form of Non-Qualified Stock Option Award Agreement granted under Marathon Oil Corporation’sCorporation's 2003 Incentive Compensation Plan (incorporated by reference to Exhibit 99.1 to Marathon Oil Corporation’sCorporation's Form 8-K, filed on May 27, 2005).

        10.20
        10.23

        Form of Officer Restricted Stock Award Agreement granted under Marathon Oil Corporation’sCorporation's 2003 Incentive Compensation Plan (incorporated by reference to Exhibit 99.2 to Marathon Oil Corporation’sCorporation's Form 8-K, filed on May 27, 2005).

        10.21
        10.24*
        Form of Performance Share Award Agreement (2004-2006 Performance Cycle) granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan, effective January 1, 2003.
        10.25
        Form of Performance Unit Award Agreement (2005-2007 Performance Cycle) granted under Marathon Oil Corporation’sCorporation's 2003 Incentive Compensation Plan (incorporated by reference to Exhibit 99.3 to Marathon Oil Corporation’sCorporation's Form 8-K filed on May 27, 2005).

        10.22
        10.26*
        Form of Cash Retention Award Agreement.
        10.27*
        Marathon Oil Company Excess Benefit Plan.
        10.28*Marathon Oil Company Deferred Compensation Plan.
        10.29*Marathon Petroleum Company LLC Excess Benefit Plan.
        10.30*Marathon Petroleum Company LLC Deferred Compensation Plan.
        10.31*Speedway SuperAmerica LLC Excess Benefit Plan.
        10.32*Speedway SuperAmerica LLC Excess Benefit Plan Amendment.
        10.33*Pilot JV Amendment to Deferred Compensation Plans and Excess Benefits Plans.
        10.34*EMRO Marketing Company Deferred Compensation Plan.
        10.35Form of Change of Control Agreement between USX Corporation and Various Officers (incorporated by reference to Exhibit 10.12 to Amendment No. 1 to the Registration Statement on Form S-4/A (File No. 333-69090) of USX Corporation filed on September 20, 2001).
        10.36Agreement between Marathon Oil Company and Clarence P. Cazalot, Jr., executed February 28, 2000 (incorporated by reference to Exhibit 10(h)10.27 to Marathon Oil Corporation’sCorporation's Annual Report on Form 10-K for the year ended December 31, 2003)2005).

        10.23


        First Amendment to Marathon Oil Company Excess Benefit Plan (incorporated by reference to Exhibit 10.1 to Marathon Oil Corporation's form 8-K filed on May 18, 2006).

        10.24


        Second Amendment to Marathon Oil Company Excess Benefit Plan (incorporated by reference to Exhibit 10.3 to Marathon Oil Corporation's form 8-K filed on October 10, 2006).

        10.25


        Marathon Oil Company Deferred Compensation Plan (incorporated by reference to Exhibit 10.28 to Marathon Oil Corporation's Annual Report on Form 10-K for the year ended December 31, 2005).

        10.26


        First Amendment to Marathon Oil Company Deferred Compensation Plan (incorporated by reference to Exhibit 10.1 to Marathon Oil Corporation's form 8-K filed on May 18, 2006).

        10.27


        Second Amendment to Marathon Oil Company Deferred Compensation Plan (incorporated by reference to Exhibit 10.4 to Marathon Oil Corporation's form 8-K filed on October 10, 2006).

        10.28


        Marathon Petroleum Company LLC Excess Benefit Plan (incorporated by reference to Exhibit 10.29 to Marathon Oil Corporation's Annual Report on Form 10-K for the year ended December 31, 2005).

        10.29


        First Amendment to Marathon Petroleum Company LLC Excess Benefit Plan (incorporated by reference to Exhibit 10.1 to Marathon Oil Corporation's form 8-K filed on October 10, 2006).

        10.30


        Marathon Petroleum Company LLC Deferred Compensation Plan (incorporated by reference to Exhibit 10.30 to Marathon Oil Corporation's Annual Report on Form 10-K for the year ended December 31, 2005).

        10.31


        First Amendment to Marathon Petroleum Company LLC Deferred Compensation Plan (incorporated by reference to Exhibit 10.2 to Marathon Oil Corporation's form 8-K filed on October 10, 2006).

        10.32


        Speedway SuperAmerica LLC Excess Benefit Plan (incorporated by reference to Exhibit 10.31 to Marathon Oil Corporation's Annual Report on Form 10-K for the year ended December 31, 2005).

        10.33


        Speedway SuperAmerica LLC Excess Benefit Plan Amendment (incorporated by reference to Exhibit 10.32 to Marathon Oil Corporation's Annual Report on Form 10-K for the year ended December 31, 2005).
         10.37 

        65



        10.34


        Pilot JV Amendment to Deferred Compensation Plans and Excess Benefits Plans (incorporated by reference to Exhibit 10.33 to Marathon Oil Corporation's Annual Report on Form 10-K for the year ended December 31, 2005).

        10.35


        EMRO Marketing Company Deferred Compensation Plan (incorporated by reference to Exhibit 10.34 to Marathon Oil Corporation's Annual Report on Form 10-K for the year ended December 31, 2005).

        10.36*


        Form of Change of Control Agreement between Marathon Oil Corporation and Various Officers.

        10.37


        Letter Agreement between Marathon Oil Company and Janet F. Clark, executed December 9, 2003 (incorporated by reference to Exhibit 10(i) to Marathon Oil Corporation’sCorporation's Annual Report on Form 10-K for the year ended December 31, 2003).
        10.38General Release dated June 11, 2005, signed by Stephen J. Lowden (incorporated by reference to Exhibit 10.1 to Marathon Oil Corporation’s Form 8-K, filed on June 16, 2005).

        12.1*

         

        Computation of Ratio of Earnings to Combined Fixed Charges and Preferred Stock Dividends.
        12.2*Computation of Ratio of Earnings to Fixed Charges.

        14.1

         

        Code of Ethics for Senior Financial Officers (incorporated by reference to Exhibit 14. to Marathon Oil Corporation’sCorporation's Form 10-K for the year ended December 31, 2004).

        21.1*

         

        List of Significant Subsidiaries.

        23.1*

         

        Consent of Independent Registered Public Accounting Firm.

        31.1*

         

        Certification of President and Chief Executive Officer pursuant to Rule 13(a)-14 and 15(d)-14 under the Securities Exchange Act of 1934.

        63


        Exhibit
        No.Description

        31.2*

         

        Certification of SeniorExecutive Vice President and Chief Financial Officer pursuant to Rule 13(a)-14 and 15(d)-14 under the Securities Exchange Act of 1934.

        32.1*

         

        Certification of President and Chief Executive Officer pursuant to 18 U.S.C. Section 1350.

        32.2*

         

        Certification of SeniorExecutive Vice President and Chief Financial Officer pursuant to 18 U.S.C. Section 1350.

        *
         *
         

        Filed herewith

        ++
        ††
         

        Marathon agrees to furnish supplementally a copy of any omitted schedule to the United States Securities and Exchange Commission upon request.

        66

        64


        Report of Independent Registered Public Accounting Firm on
        Financial Statement Schedule
        To the Stockholders of Marathon Oil Corporation:
             Our audits of the consolidated financial statements, of management’s assessment of the effectiveness of internal control over financial reporting and of the effectiveness of internal control over financial reporting referred to in our report dated March 3, 2006 appearing in the 2005 Annual Report to Shareholders of Marathon Oil Corporation (which report, consolidated financial statements and assessment are included in this Annual Report on Form 10-K) also included an audit of the financial statement schedule listed in Item 15(a)(2) of this Form 10-K. In our opinion, this financial statement schedule presents fairly, in all material respects, the information set forth therein when read in conjunction with the related consolidated financial statements.
        PricewaterhouseCoopers LLP
        Houston, Texas
        March 3, 2006

        65
        SIGNATURES


        Marathon Oil Corporation
        Schedule II – Valuation and Qualifying Accounts
        For the Years Ended December 31, 2005, 2004 and 2003
                               
            Additions    
                 
          Balance at Charged to Charged to   Balance at
          Beginning of Cost and Other   End of
        (In millions) Period Expenses Accounts Deductions(a) Period
         
        Year ended December 31, 2005
                            
        Reserves deducted in the balance sheet from the assets to which they apply:                    
         Allowance for doubtful accounts – current $6  $11  $–   $14  $3 
         Allowance for doubtful accounts – noncurrent  10   1   –    1   10 
         Tax valuation allowances:                    
          Federal  57   –    70(b)  7   120 
          State  71   –    2   1   72 
          Foreign  365   –    70   –    435 
        Year ended December 31, 2004
                            
        Reserves deducted in the balance sheet from the assets to which they apply:                    
         Allowance for doubtful accounts – current $5  $13  $–   $12  $6 
         Allowance for doubtful accounts – noncurrent  10   –    –    –    10 
         Tax valuation allowances:                    
          Federal  67   –    –    10   57 
          State  73   –    –    2   71 
          Foreign  283   –    82(c)  –    365 
        Year ended December 31, 2003
                            
        Reserves deducted in the balance sheet from the assets to which they apply:                    
         Allowance for doubtful accounts – current $6  $10  $–   $11  $5 
         Allowance for doubtful accounts – noncurrent  14   2   –    6   10 
         Tax valuation allowances:                    
          Federal  –    –    67(d)  –    67 
          State  78   –    –    5   73 
          Foreign  357   –    –    74   283 
         
        (a)Deductions for the allowance for doubtful accounts and long-term receivables include amounts written off as uncollectible, net of recoveries. Deductions in the state tax valuation allowance are due to expiring net operating losses and reduced investment tax credit allowances. Deductions in the foreign tax valuation allowance for 2003 relate to the sale of the exploration and production operations in western Canada and reduction in Norway’s valuation allowance due to additional deferred tax liabilities. Deductions in the federal valuation allowance reflect the amount of excess capital losses utilized during the year.
        (b)Reflects valuation allowances established for deferred tax assets generated in 2005, primarily related to Marathon’s re-entry into Libya of $38 million and excess capital losses related to certain derivative instruments and an asset sale of $30 million.
        (c)Reflects valuation allowances established for deferred tax assets generated in 2004, primarily related to net operating losses.
        (d)Reflects valuation allowances established for deferred tax assets generated in 2003, resulting from excess capital losses related to the sale of exploration and production operations in western Canada.

        66


        SIGNATURES
                Pursuant to the requirements of Section 13 or 15(d) of the Securities and Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.
        March 6, 2006                                            

        March 1, 2007MARATHON OIL CORPORATION

         
        By:
         

        By:


        /s/
        ALBERT G. ADKINSMICHAEL K. STEWART      

        Michael K. Stewart
          
         Albert G. Adkins
         Vice President, Accounting and Controller

                Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on March 6, 20061, 2007 on behalf of the registrant and in the capacities indicated.

        Signature

        Title
        SignatureTitle

        /s/
        THOMAS J. USHER

        Thomas J. Usher

         

        Chairman of the Board and Director

        /s/
        CLARENCE P. CAZALOT, JR.

        Clarence P. Cazalot, Jr.

         

        President & Chief Executive Officer and Director

        /s/
        JANET F. CLARK

        Janet F. Clark

         
        Senior
        Executive Vice President and Chief Financial Officer

        /s/
        ALBERT G. ADKINS
        MICHAEL K. STEWART      

        Albert G. AdkinsMichael K. Stewart

         

        Vice President, Accounting
        and Controller

        /s/
        CHARLES F. BOLDEN, JR.

        Charles F. Bolden, Jr.

         

        Director

        /s/
        DAVID A. DABERKO

        David A. Daberko

         

        Director

        /s/
        WILLIAM L. DAVIS

        William L. Davis

         

        Director

        /s/
        SHIRLEY ANN JACKSON

        Shirley Ann Jackson

         

        Director

        /s/  
        PHILIP LADER      
        Philip Lader


        Director

        /s/PHILLIP LADER

        Phillip Lader
        Director
        /s/CHARLES R. LEE

        Charles R. Lee

         

        Director

        /s/
        DENNIS H. REILLEY

        Dennis H. Reilley

         

        Director

        /s/
        SETH E. SCHOFIELD

        Seth E. Schofield

         

        Director

        /s/  
        JOHN W. SNOW      
        John W. Snow


        Director

        /s/
        DOUGLAS C. YEARLEY

        Douglas C. Yearley

         

        Director

        67

        67


        GLOSSARY OF CERTAIN DEFINED TERMS
               The following definitions apply to terms used in this document:
        AshlandAshland Inc.
        bblbarrel
        bcfbillion cubic feet
        bcfdbillion cubic feet per day
        BLMBureau of Land Management
        BOEbarrels of oil equivalent
        BOEPDbarrels of oil equivalent per day
        bpdbarrels per day
        CAAClean Air Act
        CERCLAComprehensive Environmental Response, Compensation, and Liability Act
        Clairton 1314BClairton 1314B Partnership, L.P.
        CLAMCLAM Petroleum B.V.
        CWAClean Water Act
        DOEDepartment of Energy
        downstreamrefining, marketing and transportation operations
        E&Pexploration and production
        EGEquatorial Guinea
        EGHoldingsEquatorial Guinea LNG Holdings Limited
        EPAU.S. Environmental Protection Agency
        exploratorywildcat and delineation, i.e., exploratory wells
        FASBFinancial Accounting Standards Board
        FEEDfront-end engineering and design
        FINFASB Interpretation
        GEPetrolCompania Nacional de Petroleos de Guinea Ecuatorial
        GTLgas-to-liquids
        IMVinventory market valuation
        Kinder MorganKinder Morgan Energy Partners, L.P.
        KKPLKenai Kachemak Pipeline LLC
        KMOCKhanty Mansiysk Oil Corporation
        LNGliquefied natural gas
        LOCAPLOCAP LLC
        LOOPLOOP LLC
        LPGliquefied petroleum gas
        MPCMarathon Petroleum Company LLC
        MarathonMarathon Oil Corporation and its consolidated subsidiaries
        Marathon StockUSX-Marathon Group Common Stock
        mbpdthousand barrels per day
        mcfthousand cubic feet
        MKMMKM Partners L.P.
        mmcfdmillion cubic feet per day
        MTBEmethyl tertiary-butyl ether
        NOLnet operating loss
        NOxnitrogen oxide
        NYMEXNew York Mercantile Exchange
        OCIother comprehensive income
        OPA-90Oil Pollution Act of 1990
        OTCover the counter
        PilotPilot Corporation
        PRBPowder River Basin
        PRP(s)potentially responsible party (ies)
        PTCPilot Travel Centers LLC
        RCRAResource Conservation and Recovery Act
        RM&Trefining, marketing and transportation
        SFASstatement of financial accounting standards
        SPEsspecial-purposes entities
        SSASpeedway SuperAmerica LLC
        Steel StockUSX-U. S. Steel Group Common Stock
        United States SteelUnited States Steel Corporation
        upstreamexploration and production operations
        USTsunderground storage tanks
        VIEvariable interest entity
        WTIWest Texas Intermediate

        68


        EXHIBIT INDEX
             
        Exhibit No. Description
         
         2. Plan of Acquisition, Reorganization, Arrangement, Liquidation or Succession
         
         2.1 Holding Company Reorganization Agreement, dated as of July 1, 2001, by and among USX Corporation, USX Holdco, Inc. and United States Steel LLC (incorporated by reference to Exhibit 2.1 to USX Corporation’s Form 8-K filed on July 2, 2001).
         
         2.2 Agreement and Plan of Reorganization, dated as of July 31, 2001, by and between USX Corporation and United States Steel LLC (incorporated by reference to Exhibit 2.1 to the Registration Statement on Form S-4 (File No. 333-69090) of USX Corporation filed on September 7, 2001).
         
         2.3†† Master Agreement, among Ashland Inc., ATB Holdings Inc., EXM LLC, New EXM Inc., Marathon Oil Corporation, Marathon Oil Company, Marathon Domestic LLC and Marathon Ashland Petroleum LLC, dated as of March 18, 2004 and Amendment No. 1 dated as of April 27, 2005 (incorporated by reference to Exhibit 2.1 on Amendment No. 3 to the Registration Statement on Form S-4/A (File No. 333-119694) of Marathon Oil Corporation filed on May 19, 2005).
         
         2.4†† Amended and Restated Tax Matters Agreement among Ashland Inc., ATB Holdings Inc., EXM LLC, New EXM Inc., Marathon Oil Corporation, Marathon Oil Company, Marathon Domestic LLC and Marathon Ashland Petroleum LLC, dated as of April 27, 2005 (incorporated by reference to Exhibit 2.2 on Amendment No. 3 to the Registration Statement on Form S-4/A (File No. 333-119694) of Marathon Oil Corporation filed on May 19, 2005).
         
         2.5†† Assignment and Assumption Agreement (VIOC Centers) between Ashland Inc. and ATB Holdings Inc., dated as of March 18, 2004 (incorporated by reference to Exhibit 2.3 to Marathon Oil Corporation’s Amendment No. 1 to Form 8-K/A, filed on November 29, 2004).
         
         2.6†† Assignment and Assumption Agreement (Maleic Business) between Ashland Inc. and ATB Holdings Inc., dated as of March 18, 2004 (incorporated by reference to Exhibit 2.4 to Marathon Oil Corporation’s Amendment No. 1 to Form 8-K/A, filed on November 29, 2004).
         
         2.7†† Amendment No. 2, dated as of March 18, 2004, and Amendment No. 3 dated as of April 27, 2005, to the Amended and Restated Limited Liability Company Agreement of Marathon Ashland Petroleum LLC (incorporated by reference to Exhibit 2.6 on Amendment No. 3 to the Registration Statement on Form S-4/A (File No. 333-119694) of Marathon Oil Corporation filed on May 19, 2005).
         
         3. Articles of Incorporation and Bylaws
         
         3.1 Restated Certificate of Incorporation of Marathon Oil Corporation (incorporated by reference to Exhibit 3(a) to Marathon Oil Corporation’s Annual Report on Form 10-K for the year ended December 31, 2001).
         
         3.2 By-laws of Marathon Oil Corporation (incorporated by reference to Exhibit 3(b) to Marathon Oil Corporation’s Annual Report on Form 10-K for the year ended December 31, 2002).
         
         4. Instruments Defining the Rights of Security Holders, Including Indentures
         
         4.1 Five Year Credit Agreement dated as of May 20, 2004 among Marathon Oil Corporation, the Co-Agents and other Lenders party thereto, Bank of America, N.A., as Syndication Agent, ABN Ambro Bank N.V., Citibank, N.A. and Morgan Stanley Bank, as Documentation Agents and JPMorgan Chase Bank, as Administrative Agent (incorporated by reference to Exhibit 4.1 to Marathon Oil Corporation’s Form 10-Q for the quarter ended June 30, 2004).
         
         4.2 Five Year Credit Agreement dated as of May 20, 2004 among Marathon Ashland Petroleum LLC, the Co-Agents and other Lenders party thereto, Bank of America, N.A., as Syndication Agent, ABN Ambro Bank N.V., Citibank, N.A. and Morgan Stanley Bank, as Documentation Agents and JPMorgan Chase Bank, as Administrative Agent (incorporated by reference to Exhibit 4.2 to Marathon Oil Corporation’s Form 10-Q for the quarter ended June 30, 2004).
         
         4.3 Senior Indenture dated February 26, 2002 between Marathon Oil Corporation and JPMorgan Chase Bank, as Trustee (incorporated by reference to Exhibit 4.1 to Marathon Oil Corporation’s Form 8-K, filed on March 4, 2002).
         
         4.4 Senior Indenture dated June 14, 2002 among Marathon Global Funding Corporation, Issuer, Marathon Oil Corporation, Guarantor, and JPMorgan Chase Bank, Trustee (incorporated by reference to Exhibit 4.1 to Marathon Oil Corporation’s Form 8-K, filed on June 21, 2002).
         
         4.5 Senior Supplemental Indenture No. 1 dated as of September 5, 2003 among Marathon Global Funding Corporation, Issuer, Marathon Oil Corporation, Guarantor, and JPMorgan Chase Bank, Trustee to the Indenture dated as of June 14, 2002 (incorporated by reference to Exhibit 4.1 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2003).


             
        Exhibit No. Description
            Pursuant to CFR 229.601(b)(4)(iii), instruments with respect to long-term debt issues have been omitted where the amount of securities authorized under such instruments does not exceed 10% of the total consolidated assets of Marathon. Marathon hereby agrees to furnish a copy of any such instrument to the Commission upon its request.
         
         10. Material Contracts
         
         10.1 Amended and Restated Limited Liability Company Agreement of Marathon Ashland Petroleum LLC, dated as of December 31, 1998 (incorporated by reference to Exhibit 10.1 to Marathon Oil Corporation’s Amendment No. 1 to Form 8-K/A, filed on November 29, 2004).
         
         10.2 Amendment No. 1 dated as of March 17, 2004, to the Amended and Restated Limited Liability Company Agreement of Marathon Ashland Petroleum LLC, dated as of December 31, 1998, by and between Marathon Oil Company and Ashland, Inc. (incorporated by reference to Exhibit 10.1 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2004).
         
         10.3 Tax Sharing Agreement between USX Corporation and United States Steel LLC (converted into United States Steel Corporation) dated as of December 31, 2001 (incorporated by reference to Exhibit 99.3 to Marathon Oil Corporation’s Form 8-K filed January 3, 2002).
         
         10.4 Financial Matters Agreement between USX Corporation and United States Steel LLC (converted into United States Steel Corporation) dated as of December 31, 2001 (incorporated by reference to Exhibit 99.5 to Marathon Oil Corporation’s Form 8-K, filed on January 3, 2002).
         
         10.5 Insurance Assistance Agreement between USX Corporation and United States Steel LLC (converted into United States Steel Corporation) dated as of December 31, 2001 (incorporated by reference to Exhibit 99.6 to Marathon Oil Corporation’s Form 8-K, filed on January 3, 2002).
         
         10.6 License Agreement between USX Corporation and United States Steel LLC (converted into United States Steel Corporation) dated as of December 31, 2001 (incorporated by reference to Exhibit 99.7 to Marathon Oil Corporation’s Form 8-K, filed on January 3, 2002).
         
         10.7 Marathon Oil Corporation 2003 Incentive Compensation Plan, Effective January 1, 2003 (incorporated by reference to Appendix C to Marathon Oil Corporation’s Definitive Proxy Statement on Schedule 14A filed on March 10, 2003).
         
         10.8 Marathon Oil Corporation 1990 Stock Plan, as Amended and Restated Effective January 1, 2002 (incorporated by reference to Exhibit 10(a) to Marathon Oil Corporation’s Annual Report on Form 10-K for the year ended December 31, 2001).
         
         10.9 Second Amended and Restated Marathon Oil Corporation Non-Officer Restricted Stock Plan, As Amended and Restated Effective January 2, 2002 (incorporated by reference to Exhibit 10.2 to Marathon Oil Corporation’s Amendment No. 1 to Form 10-Q/A for the quarter ended September 30, 2002).
         
         10.10 Marathon Oil Corporation Deferred Compensation Plan for Non-Employee Directors (Amended and Restated as of January 1, 2002) (incorporated by reference to Exhibit 10.12 to Marathon Oil Corporation’s Amendment No. 1 to Form 10-Q for the quarter ended September 30, 2002).
         
         10.11 First Amendment to the Marathon Oil Corporation Deferred Compensation Plan for Non-Employee Directors (Amended and Restated as of January 1, 2002) (incorporated by reference to Exhibit 10.1 to Marathon Oil Corporation’s Form 8-K, filed on December 8, 2005).
         
         10.12 Form of Non-Qualified Stock Option Grant for Chief Executive Officer granted under Marathon Oil Corporation’s 1990 Stock Plan, as amended and restated effective January 1, 2002 (incorporated by reference to Exhibit 10.2 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2004).
         
         10.13 Form of Non-Qualified Stock Option Grant for Executive Officers granted under Marathon Oil Corporation’s 1990 Stock Plan, as amended and restated effective January 1, 2002 (incorporated by reference to Exhibit 10.3 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2004).
         
         10.14* Form of Non-Qualified Stock Option Grant for MAP officers granted under Marathon Oil Corporation’s 1990 Stock Plan, as amended and restated effective January 1, 2002.
         
         10.15 Form of Non-Qualified Stock Option with Tandem Stock Appreciation Right Award Agreement for Chief Executive Officer granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.4 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2004).
         
         10.16 Form of Non-Qualified Stock Option with Tandem Stock Appreciation Right Award Agreement for Executive Committee members granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.5 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2004).


             
        Exhibit No. Description
         10.17 Form of Non-Qualified Stock Option with Tandem Stock Appreciation Right Award Agreement for Officers granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.6 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2004).
         
         10.18* Form of Non-Qualified Stock Option Award Agreement for MAP officers granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan, effective January 1, 2003.
         
         10.19 Form of Stock Appreciation Right Award Agreement for Chief Executive Officer granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.7 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2004).
         
         10.20 Form of Stock Appreciation Right Award Agreement for Executive Committee members granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.8 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2004).
         
         10.21 Form of Stock Appreciation Right Award Agreement for Officers granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan, effective January 1, 2003 (incorporated by reference to Exhibit 10.9 to Marathon Oil Corporation’s Form 10-Q for the quarter ended September 30, 2004).
         
         10.22 Form of Non-Qualified Stock Option Award Agreement granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan (incorporated by reference to Exhibit 99.1 to Marathon Oil Corporation’s Form 8-K, filed on May 27, 2005).
         
         10.23 Form of Officer Restricted Stock Award Agreement granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan (incorporated by reference to Exhibit 99.2 to Marathon Oil Corporation’s Form 8-K, filed on May 27, 2005).
         
         10.24* Form of Performance Share Award Agreement (2004-2006 Performance Cycle) granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan, effective January 1, 2003.
         
         10.25 Form of Performance Unit Award Agreement (2005-2007 Performance Cycle) granted under Marathon Oil Corporation’s 2003 Incentive Compensation Plan (incorporated by reference to Exhibit 99.3 to Marathon Oil Corporation’s Form 8-K filed on May 27, 2005).
         
         10.26* Form of Cash Retention Award Agreement.
         
         10.27* Marathon Oil Company Excess Benefit Plan.
         
         10.28* Marathon Oil Company Deferred Compensation Plan.
         
         10.29* Marathon Petroleum Company LLC Excess Benefit Plan.
         
         10.30* Marathon Petroleum Company LLC Deferred Compensation Plan.
         
         10.31* Speedway SuperAmerica LLC Excess Benefit Plan.
         
         10.32* Speedway SuperAmerica LLC Excess Benefit Plan Amendment.
         
         10.33* Pilot JV Amendment to Deferred Compensation Plans and Excess Benefits Plans.
         
         10.34* EMRO Marketing Company Deferred Compensation Plan.
         
         10.35 Form of Change of Control Agreement between USX Corporation and Various Officers (incorporated by reference to Exhibit 10.12 to Amendment No. 1 to the Registration Statement on Form S-4/A (File No. 333-69090) of USX Corporation filed on September 20, 2001).
         
         10.36 Agreement between Marathon Oil Company and Clarence P. Cazalot, Jr., executed February 28, 2000 (incorporated by reference to Exhibit 10(h) to Marathon Oil Corporation’s Annual Report on Form 10-K for the year ended December 31, 2003).
         
         10.37 Letter Agreement between Marathon Oil Company and Janet F. Clark, executed December 9, 2003 (incorporated by reference to Exhibit 10(i) to Marathon Oil Corporation’s Annual Report on Form 10-K for the year ended December 31, 2003).
         
         10.38 General Release dated June 11, 2005, signed by Stephen J. Lowden (incorporated by reference to Exhibit 10.1 to Marathon Oil Corporation’s Form 8-K, filed on June 16, 2005).
         
         12.1* Computation of Ratio of Earnings to Combined Fixed Charges and Preferred Stock Dividends.
         
         12.2* Computation of Ratio of Earnings to Fixed Charges.
         
         14.1 Code of Ethics for Senior Financial Officers (incorporated by reference to Exhibit 14. to Marathon Oil Corporation’s Form 10-K for the year ended December 31, 2004).
         
         21.1* List of Significant Subsidiaries.


        Exhibit No.Description
        23.1*Consent of Independent Registered Public Accounting Firm.
        31.1*Certification of President and Chief Executive Officer pursuant to Rule 13(a)-14 and 15(d)-14 under the Securities Exchange Act of 1934.
        31.2*Certification of Senior Vice President and Chief Financial Officer pursuant to Rule 13(a)-14 and 15(d)-14 under the Securities Exchange Act of 1934.
        32.1*Certification of President and Chief Executive Officer pursuant to 18 U.S.C. Section 1350.
        32.2*Certification of Senior Vice President and Chief Financial Officer pursuant to 18 U.S.C. Section 1350.
          * Filed herewith
        †† Marathon agrees to furnish supplementally a copy of any omitted schedule to the United States Securities and Exchange Commission upon request.