Our investors benefited from a 91% total return in 2010. As we completed the year, we continued to improve top line trends, expand margins, generate significant free cash flow and we achieved our guidance expectations. We continued to see strong growth in our strategic revenue as we aggressively deployed fiber-based broadband services. Strategic revenue is a greater contributor in each of our three business units. Overall, strategic revenue now represents 40% of the company's total revenue.
Our effort to improve margins is another area where we had strong success in 2010. For the full year, our adjusted EBITDA margin was once again at its best level since the merger with U S West in 2000. We also continued to strengthen our financial flexibility by improving the balance sheet. Our progress was recognized earlier this year by a rating agency upgrade. During the fourth quarter, we redeemed all of the $1.1 billion outstanding convertible notes. And as of today, we've achieved our stated annual debt reduction goal of $3.5 billion announced in February 2010.
In addition, I'm very pleased with the progress we're making toward the completion of our merger with CenturyLink. We have reached several key milestones in the approval process, and we continue to make progress with the remaining agencies and commissions required to review the transaction. To date, we have received approval in 18 states. In addition to the FCC, we have four states remaining to review and approve the transaction. While the pace of regulatory approvals can be difficult to predict, we currently expect to receive all required regulatory approvals in the first quarter. That being the case. We are currently planning toward an April 1 closing date, and activities are well underway in the planning process for the integration of the two companies, including naming the next tiers in the organization structure. Of course, our target dates for regulatory approval and closing could be pushed back as these final processes unfold. But we continue to believe that we will receive all approvals and close by April 1.