UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-Q

For the quarterly period ended JuneSeptember 30, 2009

or

Commission file number: 1-6686

THE INTERPUBLIC GROUP OF COMPANIES, INC.

(Exact name of registrant as specified in its charter)

1114 Avenue of the Americas, New York, New York 10036

(Address of principal executive offices) (Zip Code)

(212) 704-1200

(Registrant’s telephone number, including area code)

(Former name, former address and former fiscal year, if changed since last report)

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 (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Yesx    No¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).

Yesx¨    No¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definition of “large accelerated filer,” “accelerated filer,” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

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

Yes¨    Nox

The number of shares of the registrant’s common stock outstanding as of July 17,October 16, 2009 was 486,111,579.486,118,123.

INDEX

INFORMATION REGARDING FORWARD-LOOKING DISCLOSURE

This quarterly report on Form 10-Q contains forward-looking statements. Statements in this report that are not historical facts, including statements about management’s beliefs and expectations, constitute forward-looking statements. Without limiting the generality of the foregoing, words such as “may,” “will,” “expect,” “believe,” ”anticipate,“anticipate,” “intend,” “could,” “would,” “estimate,” “continue” or comparable terminology are intended to identify forward-looking statements. These statements are based on current plans, estimates and projections, and are subject to change based on a number of factors, including those outlined under Item 1A, Risk Factors, in our most recent annual report on Form 10-K. Forward-looking statements speak only as of the date they are made, and we undertake no obligation to update publicly any of them in light of new information or future events.

Forward-looking statements involve inherent risks and uncertainties. A number of important factors could cause actual results to differ materially from those contained in any forward-looking statement. Such factors include, but are not limited to, the following:

Investors should carefully consider these factors and the additional risk factors outlined in more detail under Item 1A, Risk Factors, in our most recent annual report on Form 10-K.

Part I – FINANCIAL INFORMATION

THE INTERPUBLIC GROUP OF COMPANIES, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF OPERATIONS

(Amounts in Millions, Except Per Share Amounts)

(Unaudited)

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

THE INTERPUBLIC GROUP OF COMPANIES, INC. AND SUBSIDIARIES

CONSOLIDATED BALANCE SHEETS

(Amounts in Millions)

(Unaudited)

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

THE INTERPUBLIC GROUP OF COMPANIES, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF CASH FLOWS

(Amounts in Millions)

(Unaudited)

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

THE INTERPUBLIC GROUP OF COMPANIES, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY AND COMPREHENSIVE INCOME

(Amounts in Millions)

(Unaudited)

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

THE INTERPUBLIC GROUP OF COMPANIES, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY AND COMPREHENSIVE INCOME – (CONTINUED)

(Amounts in Millions)

(Unaudited)

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

Notes to Consolidated Financial Statements

(Amounts in Millions, Except Per Share Amounts)

(Unaudited)

Note 1:  Basis of Presentation

The unaudited Consolidated Financial Statements have been prepared by The Interpublic Group of Companies, Inc. (together with its subsidiaries, the “Company,” “Interpublic,” “we,” “us” or “our”) in accordance with accounting principles generally accepted in the United States of America and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC” or the “Commission”) for reporting interim financial information on Form 10-Q. Accordingly, they do not include certain information and disclosures required for complete financial statements. The preparation of financial statements in accordance with accounting principles generally accepted in the United States requires us to make judgments, assumptions and estimates that affect the amounts reported and disclosed. Actual results could differ from those estimates. The consolidated results for interim periods are not necessarily indicative of results for the full year and should be read in conjunction with our 2008 Annual Report on Form 10-K as filed on February 27, 2009 and the revisions made on Form 8-K dated as of June 8, 2009.

In the opinion of management, these unaudited Consolidated Financial Statements include all adjustments of a normal and recurring nature necessary for a fair statement of the information for each period contained therein. We have evaluated subsequent events through the filing of this Form 10-Q on October 28, 2009 with the SEC, and determined there have not been any events that have occurred that would require adjustments to our unaudited Consolidated Financial Statements. Certain reclassifications have been made to prior periods to conform to the current period presentation.

Note 2:  Debt and Credit Arrangements

Long-Term Debt

A summary of the carrying amounts and fair values of our long-term debt is as follows.

Notes to Consolidated Financial Statements – (continued)

(Amounts in Millions, Except Per Share Amounts)

(Unaudited)

Senior Notes due 2017

On June 15, 2009 we issued $600.0 in aggregate principal amount of 10.00% Senior Unsecured Notes due 2017 (the “2017 Notes”) at 97.958% of par through a private placement. As a result, the 2017 Notes were reflected on our unaudited Consolidated Balance Sheet at their fair value at issuance, or $587.7. The discount of $12.3 will be amortized through the

Notes to Consolidated Financial Statements – (continued)

(Amounts in Millions, Except Per Share Amounts)

(Unaudited)

maturity date, July 15, 2017, using the effective interest method. Interest is payable semi-annually in arrears on January 15^th and July 15^th of each year, commencing on January 15, 2010. Capitalized direct fees of $15.7$15.8 related to the issuance of the 2017 Notes will be amortized in interest expense through the maturity date. Consistent with our other debt securities, the 2017 Notes include covenants that, among other things, limit our liens and the liens of our consolidated subsidiaries, but do not require us to maintain any financial ratios or specified levels of net worth or liquidity.

We used the proceeds of the 2017 Notes primarily to fund our tender offers, described below, to purchase outstanding 7.25% Notes due 2011 (the “2011 Notes”) and Floating Rate Notes due 2010 (the “2010 Notes”). Excess funds raised in the offering but not used in the tender offers can be used for the repayment, repurchase or redemption of other indebtedness, general corporate purposes and working capital.

At any time prior to July 15, 2013, we may, at our option, redeem all or some of the 2017 Notes at their principal amount plus a make-whole premium and accrued and unpaid interest. At any time on or after July 15, 2013, we may, at our option, redeem the 2017 Notes, in whole or in part, at the following redemption prices, expressed as a percentage of principal amount, set forth below, plus accrued and unpaid interest, if redeemed during the twelve monthtwelve-month period beginning on July 15^th of the years indicated below.

If we have a change of control event, each holder of the 2017 Notes will have the right to require us to repurchase all or any part of that holder’s notes. We will offer payment innotes for cash equal to 101.00% of the aggregate principal amount of the 2017 Notes repurchased plus accrued and unpaid interest to the date of repurchase.

On October 26, 2009, we exchanged $600.0 principal amount of the 2017 Notes for an equal amount of new 2017 Notes with substantially identical terms as the original notes, except the new notes have no transfer restrictions under the federal securities laws. Completion of the exchange offer will not affect any of the financial terms of the outstanding 2017 Notes.

Tender Offers

On June 8, 2009, we launched tender offers to purchase, for cash, (i) any and all of our $250.0 5.40% Notes due 2009 (the “2009 Notes”) and (ii) up to $500.0 in aggregate principal amount of our outstanding 2011 Notes and 2010 Notes with an early tender date of June 19, 2009 and an expiration date of July 6, 2009. We used the proceeds from the offering of the 2017 Notes first to purchase tendered 2011 Notes, and then to purchase on a pro-rated basis tendered 2010 Notes. We used cash on hand to purchase the tendered 2009 Notes. The tendered notes that were accepted for purchase received accrued and unpaid interest to, but not including, the settlement date. The purchase price for our tendered notes per $1,000 aggregate principal amount in whole dollars is listed below.

On June 22, 2009, we settled early tenders of the 2009 Notes and the 2011 Notes. We purchased $213.9 aggregate principal amount of the 2009 Notes and $463.7 aggregate principal amount of the 2011 Notes. Cash paid to purchase the

Notes to Consolidated Financial Statements – (continued)

(Amounts in Millions, Except Per Share Amounts)

(Unaudited)

2009 Notes and 2011 Notes that were tendered during the early tender period, including accrued and unpaid interest, was $711.4. The 2010 Notes tendered during the early tender period that were accepted for purchase received the early tender

Notes to Consolidated Financial Statements – (continued)

(Amounts in Millions, Except Per Share Amounts)

(Unaudited)

price; they were not, however, considered for purchase until the final settlement date. Holders who did not tender the 2009 Notes, 2011 Notes or 2010 Notes during the early tender period were able to tender their notes before the expiration of the tender period on July 6, 2009, but did not receive an early tender premium.

In accordance with Statementauthoritative guidance regarding the extinguishment of Financial Accounting Standards (“SFAS”) No. 140,Accounting for Transfersliabilities and Servicing of Financial Assetsdebt modifications and Extinguishment of Liabilitiesand APB Opinion No. 26,Early Extinguishment of Debt,extinguishments, the settlement of our tender offers werewas treated as a debt extinguishment because we were relieved of our debt obligation upon settlement. We compared the proportionate share of the net carrying amount, which includes the carrying amount due at maturity, adjusted for unamortized discounts, debt issuance costs and gains and losses on interest rate swaps, if applicable, to the reacquisition price for each of the tendered 2009 Notes and 2011 Notes. Since the reacquisition price was greater than the net carrying amount for the 2009 Notes and the 2011 Notes, we recorded a charge of $24.6 reflected in other income (expense) income,, net in the unaudited Consolidated Statement of Operations during the second quarter of 2009.

Subsequent to June 30, 2009

On July 7, 2009, we settled tenders for the 2009 Notes, 2011 Notes and 2010 Notes that had not been settled at the early settlement date. We purchased less than $0.1 aggregate principal amount of the 2009 Notes and 2011 Notes, as well as $36.3 aggregate principal amount of the 2010 Notes. Cash paid to purchase the 2009 Notes, 2011 Notes and 2010 Notes that were purchased at the end of the final tender period, including accrued and unpaid interest, was $36.5. As a result of the final settlement of our tender offers, we will recordrecorded a debt extinguishment charge of approximately $0.8$0.9 reflected in other income (expense) income,, net in the unaudited Consolidated Statement of Operations during the third quarter of 2009.

Redemption

On September 14, 2009, we redeemed all of our 2009 Notes that remained outstanding and that were scheduled to mature on November 15, 2009. Cash paid to redeem the $36.0 aggregate principal amount of the 2009 Notes, including accrued and unpaid interest, was $37.0. As a result of the redemption, we recorded a debt extinguishment charge of $0.3 reflected in other income (expense), net in the unaudited Consolidated Statement of Operations during the third quarter of 2009.

Interest Rate Swaps

In July and August of 2009, we entered into a series of interest rate swap agreements related to our 6.25% Senior Unsecured Notes due 2014 (the “6.25% Notes”). These swap agreements economically to convert $100.0$250.0 notional amount of our $350.0 6.25% Notes from fixed rate to floating rate debt. We enter into interest rate swaps for risk management purposes, and not for speculative purposes, to manage our exposure to changes in interest rates and to maintain an appropriate mix of fixed and floating rate debt. The interest rate swap agreements became effective July 16 and July 21, 2009 and have a maturity ofmature on November 15, 2014, coinciding with the maturity of the 6.25% Notes. We pay a variable interest rate based upon the three-month U.S. LIBOR rate plus a fixed spread and receive a fixed interest rate of 6.25%. The variable interest rate is reset quarterly, and we make our interest payments quarterly on February 15^th,15th, May 15^th,15th, August 15^th15th and November 15^th.15th. We receive fixed payments semi-annually on May 15^th15th and November 15^th. We account for the15th. The interest rate swap agreements have qualified for hedge accounting as a fair value hedge, and we will continue to evaluate these agreements for the appropriateness of hedge accounting throughout the hedge period. We recognize the changes in the fair value of the swap should offsetas well as the changes in the fair value of the $100.0 fixed-rateunderlying debt attributable toin interest expense. As of September 30, 2009, the change in the three-month U.S. LIBOR rate. At inception, the interest ratefinancial statement impact of these swap agreements met the criteria for the short-cut method under SFAS No. 133,Accounting for Derivative Instruments and Hedging Activities, and thus will have no impact on ourwas negligible.

Notes to Consolidated Balance Sheet.Financial Statements – (continued)

(Amounts in Millions, Except Per Share Amounts)

(Unaudited)

Credit Arrangements

A summary of our credit facilities is listed below.

On June 15, 2009, our $750.0 Three-Year Credit Agreement, dated as of June 13, 2006 (the “2006 Credit Agreement”) expired. As of the expiration date, there was no outstanding principal, and the outstanding letters of credit were replaced with

Notes to Consolidated Financial Statements – (continued)

(Amounts in Millions, Except Per Share Amounts)

(Unaudited)

letters of credit issued under our $335.0 Three-Year Credit Agreement, dated as of July 18, 2008 (the “2008 Credit Agreement”). In connection with the 2006 Credit Agreement we issued 67.9 warrants, consisting of 29.1 capped warrants (the “Capped Warrants”) and 38.8 uncapped warrants (the “Uncapped Warrants”) with a stated exercise date of June 15, 2009. We have elected that, should there be any settlement, eachFor the Capped Warrants, the exercise price was $9.89 per warrant, but the amount deliverable upon exercise was capped so a holder will be paid in cash.would not benefit from appreciation of the common stock above $12.36 per share. For the Uncapped Warrants, the exercise price was $11.91 per warrant. The amount to be paid, if any, will be based on the difference between the stated exercise price of the warrantcapped and uncapped warrants was greater than the market price of one share of our common stock calculated over a 30-trading-day period between June 18, 2009 and July 29, 2009. For the Capped Warrants, the exercise price is $9.89 per warrant, but the amount deliverable upon exercise is capped2009, so a holder willwe did not benefit from appreciation of thehave to make any cash payments or issue any common stock above $12.36 per share. Forto settle the Uncapped Warrants, the exercise price is $11.91 per warrant.capped or uncapped warrants.

On May 13, 2009, we entered into Amendment No. 1 to the 2008 Credit Agreement to preserve our ability to use the 2008 Credit Agreement in the event of any bankruptcy or related event with respect to General Motors Corporation (“GM”) and/or any of its affiliates. Amendment No. 1 modifies the definition of EBITDAearnings before interest, taxes, depreciation and amortization (“EBITDA”) under the 2008 Credit Agreement to exclude from the determination of consolidated EBITDA any effects arising from any bankruptcy or other adverse event with respect to GM and/or any of its affiliates, limited to an aggregate amount of $150.0 of cash charges and an aggregate amount of $100.0 of non-cash charges. On June 1, 2009, GM and certain of its U.S. affiliates filed voluntary petitions for relief under Chapter 11 of the U.S. Bankruptcy Code. We did not incur any cash or non-cash charges related to GM during the second quarter of 2009.

On June 5, 2009, we entered into Amendment No. 2 to the 2008 Credit Agreement to modify terms of the financial covenants. As of the end of each fiscal quarter, we will be required to maintain an (i) an interest coverage ratio (EBITDA to net interest expense plus cash dividends on convertible preferred stock) for the four quarters then ended of not less than 3.75 to 1, (ii) a leverage ratio (debt as of such date to EBITDA) for the four quarters then ended of not greater than 3.25 to 1, and (iii) minimum EBITDA for the four quarters then ended of not less than $550.0 through June 30, 2010 and not less than $600.0 thereafter. As of JuneSeptember 30, 2009, we were in compliance with all applicable covenants.

As of JuneSeptember 30, 2009 and December 31, 2008, there were no borrowings under our committed credit facilities. However, there were borrowings under the uncommitted facilities made by several of our subsidiaries outside the U.S.international subsidiaries. We have guaranteed the repayment of some of these borrowings made by certain subsidiaries. The weighted-average interest rate on outstanding balances under the uncommitted short-term facilities as of JuneSeptember 30, 2009 and December 31, 2008 was approximately 1% and 3%, respectively.

Notes to Consolidated Financial Statements – (continued)

(Amounts in Millions, Except Per Share Amounts)

(Unaudited)

Note 3:  Earnings (Loss) Per Share

Earnings (loss) per basic common share available to IPG common stockholders equals net income (loss) available to IPG common stockholders divided by the weighted average number of common shares outstanding for the applicable period. Diluted earnings (loss) per share available to IPG common stockholders equals net income (loss) available to IPG common stockholders adjusted to exclude, if dilutive, preferred stock dividends, allocation to participating securities and interest expense related to potentially dilutive securities calculated using the effective interest rate, divided by the weighted average number of common shares outstanding, plus any additional common shares that would have been outstanding if potentially dilutive shares had been issued.

In periods when we generate income, we calculate basic earnings per share available to IPG common stockholders using the two-class method, pursuant to Emerging Issues Task Force (“EITF”) Issue No. 03-6,authoritative guidance for earnings per shareParticipating Securities and the Two-Class Method under SFAS Statement No. 128.. The two-class method is required as our 4.50% Convertible Senior Notes qualify as participating securities, having the right to receive dividends or dividend equivalents should dividends be declared on common stock. Under this method, earnings for the period (after deduction for contractual preferred stock dividends) are allocated on a pro-rata basis to the common stockholders and to the holders of participating securities based on their right to receive dividends. We do not use the two-class method in periods when we generate a loss as the holders of the 4.50% Convertible Senior Notes do not participate in losses.

Notes to Consolidated Financial Statements – (continued)

(Amounts in Millions, Except Per Share Amounts)

(Unaudited)

The two-class method could also be required for our redeemable noncontrolling interests, which have been reflected as “mezzanine equity” in the unaudited Consolidated Balance Sheets as a result of our adoption of EITF Topic No. D-98,“Classificationauthoritative guidance for classification and Measurementmeasurement of Redeemable Securities(“EITF D-98”).redeemable securities. Each reporting period, redeemable noncontrolling interests will be reported at their estimated redemption value, but not less than their initial fair value. Any adjustment to the redemption value will also impact additional paid-in capital, but will not impact net income (loss). Adjustments as a result of currency translation will affect the redeemable noncontrolling interest balance, but not additional paid-in capital. To the extent that the redemption value increases and exceeds the then currentthen-current fair value of a redeemable noncontrolling interest, net income (loss) available to IPG common stockholders (used to calculate earnings (loss) per share) could be reducednegatively impacted by that increase, subject to certain limitations. The partial or full recovery of these reductions to net income (loss) available to IPG common stockholders (used to calculate earnings (loss) per share) is limited to cumulative prior periodprior-period reductions.