Delivering Strong Financial Results
The flexibility and strength of our operating model, and tremendous efforts of our leadership and teams, allowed us to end 2020 with solid results that are in line with our objectives to protect our financial position and maintain our margin, which we had set at the beginning of the pandemic.
Despite a decrease in revenues, we completed the year in a strong financial position with a healthy backlog, an improved adjusted EBITDA margin, and record cash flows, providing a solid platform for continued success in 2021.
Revenues and net revenues for the year reached $8.8 billion and $6.9 billion, respectively, down 1.3% and 0.4% compared to 2019. Backlog stood at $8.4 billion, representing 11.5 months of revenues, up $289.5 million or 3.6% compared to last year, including organic growth of 2.4%. We also reported an adjusted EBITDA of $1,053.7 million, slightly surpassing our expectations, and an adjusted EBITDA margin of 15.4%, up from 15.1% last year.
In terms of other metrics, we were pleased to report that days sales outstanding (DSO) continued to decrease and reached 63 days at the end of 2020, well below our outlook range of 73 to 78 days. Our free cash flow for the year came in at $735.3 million, representing 266% of net earnings attributable to shareholders.
The initial decisions brought forward by this challenging year were made out of necessity. After ensuring the safety and wellbeing of our people, in addition to taking actions to safeguard our business, our mindset shifted to expanding on what could be possible in this new landscape to set ourselves up for long-term success.
Focusing on Strategic Growth
In the second quarter of 2020, we completed an equity financing of over $570 million, to provide us with the maximum financial flexibility to continue to pursue our strategic ambitions. We once again were pleased to count on the support of our anchor shareholders as well as other institutional investors and the broader investment community.
Acquisitions have always been an integral part of our growth story. We have a proven track record of selecting successful and accretive acquisition targets according to criteria that correspond to our present and future business needs and market conditions. Though the pandemic and corresponding economic downturn may have made these activities more complex, we continued to explore the possibilities to bring value to all our stakeholders.
We ended the year by entering into an agreement to acquire Golder, a global consulting firm with approximately 7,000 people and an outstanding reputation in earth sciences and environmental consulting. Golder marks another exciting step in our journey to become the reference in our industry, allowing us to achieve several key milestones in our 2019-2021 Global Strategic Plan.