Thank you, Dan. Good morning, everyone.
Before I discuss our fourth quarter financial performance, I'd like to recap a few housekeeping items, some of which impact our year-over-year comparability.
First, as part of our ongoing effort to actively manage our asset base, we sold 50% of our investment in AuditBoard, receiving proceeds of $12.8 million in the fourth quarter of 2019. This transaction resulted in a combined realized and unrealized gain of $13.6 million, freeing up cash for other uses, including debt repayment.
Next, certain pension plan participants elected to receive lump sum pension payments in the fourth quarter, which resulted in a noncash settlement charge of $3.9 million in the fourth quarter.
We also paid off the remaining balance of our term loan credit facility of $72.5 million in the fourth quarter.
As a result, we recognized a pretax loss on extinguishment of debt of $4.1 million related to unamortized debt issuance cost and the original issuance discount. This loss is included in our fourth quarter 2019 interest expense. All 3 of these items are excluded from our non-GAAP results.
GAAP income tax expense for the fourth quarter of 2019 was a benefit of $2 million due to favorable return to provision adjustments, primarily related to our foreign-derived intangible income deduction, state and local income taxes and our research and development credits.
Finally, as we have discussed on the last several calls, we completed the sale of our Language Solutions business in the third quarter of 2018.
For the year, the sale negatively impacts the year-over-year net sales comparison by $41.8 million, and negatively impacted our gross profit and non-GAAP adjusted EBITDA comparisons by approximately $12 million and $3 million, respectively, inclusive of net stranded costs. The sale did not impact the year-over-year comparisons in the fourth quarter of 2019.
Keeping these items in mind, let's review our fourth quarter financial results. On a consolidated basis, net sales for the fourth quarter of 2019 were $190.3 million, a decrease of $10 million or 5% from the fourth quarter of 2018. After adjusting for the 2018 acquisition of eBrevia and the impact of foreign exchange rates, organic net sales decreased 5.2% as a reacceleration in growth in our SaaS solutions, led by ActiveDisclosure and FundSuite Arc, was more than offset by lower capital markets transactional and compliance print volume as well as lower investment markets, mutual fund and health care print volume.
Services net sales in the fourth quarter increased by $2.4 million or 1.8% compared to the fourth quarter of 2018, primarily driven by growth in our SaaS solutions. Products net sales decreased by $12.4 million or 18.2%, due primarily to lower investment markets, mutual fund and health care print volume as well as lower capital markets transactional and compliance print volume.
Fourth quarter gross margin was 37.9% or 270 basis points higher than the fourth quarter of 2018, primarily driven by a favorable mix, featuring higher margin SaaS -- services net sales, combined with lower overall print volume.
Non-GAAP SG&A expense in the quarter was $46 million, $5.1 million lower than the fourth quarter of 2018.
As a percentage of revenue, non-GAAP SG&A was 24.2%, a decrease of 130 basis points from the fourth quarter of 2018. The decrease in non-GAAP SG&A expense is primarily due to the impact of ongoing cost savings initiatives.
Our fourth quarter non-GAAP adjusted EBITDA was $26.1 million, an increase of $6.7 million from the fourth quarter of 2018.
Our fourth quarter non-GAAP adjusted EBITDA margin was 13.7%, an increase of 400 basis points from the fourth quarter of 2018, again, primarily driven by the impact of ongoing cost savings initiatives and a more favorable revenue mix.
Turning now to our segment results. Net sales in our U.S. segment were $161.7 million in the fourth quarter of 2019, a decrease of 5.3% from last year's fourth quarter. On an organic basis, net sales were down 5.7%. Net sales in U.S. capital markets decreased 6.8% on an organic basis, due primarily to lower transactional and compliance activity, partially offset by growth in our SaaS solutions, primarily in ActiveDisclosure. Net sales in U.S. investment markets decreased 4.4% on an organic basis, driven by lower mutual fund and health care print volume, partially offset by solid growth in FundSuite Arc.
Non-GAAP adjusted EBITDA margin for the segment of 16.7% increased 250 basis points from the fourth quarter of 2018, primarily due to the impact of ongoing cost savings initiatives. Net sales in our International segment were $28.6 million in the fourth quarter of 2019, a decrease of 3.4% from the fourth quarter of 2018.
On an organic basis, excluding the impact of changes in foreign exchange rates, net sales in the fourth quarter were down 3%. Non-GAAP adjusted EBITDA margin for the segment was 11.9%, an increase of 510 basis points from the fourth quarter of 2018. The increase in non-GAAP adjusted EBITDA margin was primarily due to the impact of ongoing cost savings initiatives.
Our fourth quarter 2019 non-GAAP unallocated corporate expenses, excluding depreciation and amortization, were $4.3 million, a decrease of $2.5 million from the fourth quarter of last year. The decline in unallocated corporate cost was primarily driven by cost savings initiatives.
Consolidated free cash flow in the quarter was $49 million, $7.4 million higher than the fourth quarter of 2018, primarily due to higher EBITDA, lower interest payments and lower capital expenditures.
As we have discussed on the last few calls, we are actively engaged in an initiative to improve our quote-to-cash processes with the goal of driving better cash conversion.
We are already starting to see results in the first quarter of 2020, with improvement in our year-over-year cash flow through the first several weeks of the year, and are targeting ongoing improvement in this area throughout the year. We paid off our term loan in the fourth quarter of 2019, ending the year with $296 million of total debt and $278.8 million of net debt, with nothing drawn on our net revolver, and net available liquidity of $248.8 million.
As of December 31, 2019, our net leverage ratio was 2.0x, flat from a year ago.
Lastly, at year-end 2019, our pension and other postretirement plans were $60.2 million underfunded, a decline in funding levels of $7.7 million compared to year-end 2018. With that covered, let me now provide some color on the full year 2020 guidance summarized in this morning's press release.
Specifically, we expect 2020 total consolidated net sales to be in the range of $860 million to $880 million, staying essentially flat year-over-year at the midpoint, as SaaS net sales growth of low double digits is offset by the proactive reductions in less profitable sales that Dan mentioned earlier as well as any potential unfavorable election year impacts to our transactional business, which we are assuming to be flat to slightly down for the year.
We expect our non-GAAP adjusted EBITDA to be in the range of $140 million to $145 million, up approximately 4% as we continue to see the benefits of our improved revenue mix as well as the continued run rate impact of our ongoing cost savings initiatives. Depreciation and amortization is expected to be approximately $55 million.
We expect interest expense of approximately $30 million.
Our full year non-GAAP tax rate is expected to be in the range of 29% to 31%. We project the full year fully diluted weighted average share count to be approximately 35 million shares, not including any potential impact of the share repurchase program that Dan mentioned earlier.
We expect capital expenditures to be approximately $35 million, down nearly $10 million from 2019, primarily related to the onetime investment in digital print equipment in 2019. And lastly, we expect free cash flow in the range of $35 million to $40 million.
Regarding our outlook for the first quarter, we're expecting net sales to be in the range of $220 million to $230 million, down approximately 2% year-over-year at the midpoint, due largely to a $4 million nonrecurring special proxy project in U.S. investment markets in the first quarter of 2019 as well as the expected unfavorable impacts to our business related to the coronavirus outbreak, specifically in our International segment.
Regarding profitability, we expect our non-GAAP adjusted EBITDA margin to improve compared to the first quarter of 2019, as we continue to see the run rate impact of our ongoing cost savings initiatives show up in the results.
Regarding seasonality of our cash flow, our normal cash flow pattern has us as a net user of cash in the first half of the year, generating most of our cash in the back half of the year. We do, however, expect to see improvements in cash flow related to the quote-to-cash initiative I mentioned earlier, some of which, we expect to see in the first half of the year.
Finally, we are planning to make changes to certain disclosures in the first quarter of 2020, aimed at providing additional clarity around the performance of our traditional and SaaS offerings. We look forward to sharing these changes with you beginning with our first quarter 2020 results.
And with that, I'll turn it back to Dan.