Finally, I'd like to remind you that all forward-looking statements made during this conference call are subject to various risks and uncertainties that could cause actual results to differ materially from expectations. These factors are discussed more fully in the earnings release and in the company's SEC filings. Copies of these SEC reports are available from the SEC and from the Unisys investor website.
And now I'd like to turn the call over to Ed.
J. Edward Coleman
Thanks, Niels. Hello, everyone, and thank you for joining us today to discuss our first quarter 2012 financial results.
We reported increased profits on higher revenue for the first quarter, and Janet will go through the numbers in detail, but please see Page 4 of the presentation for highlights.
We reported diluted earnings per share of $0.30 compared to a diluted net loss of $0.95 in the first quarter of 2011. Excluding debt reduction charges and pension expense in both years, our non-GAAP earnings per share increased to $0.97 from a non-GAAP loss of $0.04 a year ago.
Revenue grew 2% year-over-year overall and 3% in our services business. This was the second quarter in the past 3 that we've grown our top line. We've done this despite continued weakness in our U.S. Federal business where conditions remained challenging. Margins improved in our services business, although we still have work to do to get to our goal of a consistent 8% to 10% operating profit margin.
Our technology business delivered strong margins in the quarter on 5% lower revenue as we benefited from a richer mix of enterprise software.
We also continued to make progress in reducing debt during the quarter, retiring an additional $66 million of high-coupon notes. Since September 2010, we've cut our outstanding debt by more than $540 million or nearly 2/3 and we are now 87% of the way toward our year-end 2013 debt reduction goal. These actions have reduced our annualized interest expense by $69 million.