As you listen to today's call, we will discuss certain non-GAAP financial measures and supplemental key performance metrics by revenue categories, headcount and additional expense detail. This information, including reconciliations to the most comparable GAAP measures, can be found in today's earnings release and under our Investor Relations tab on our website, www.neustar.biz.
With that I'm pleased to introduce Neustar's President and Chief Executive Officer, Lisa Hook. Lisa?
Lisa A. Hook
And thank you, Mr. Dave. Let me start by reminding you all that we have 4 key priorities this year. We are hitting our financial targets, of course, positioning to win a renewal of the NPAC contract, integrating TARGUSinfo and transforming our culture. First, let me offer some perspective on our strong performing in the quarter, then Paul will walk you through our results with more detail and texture.
Second quarter results exceeded our expectations and demonstrates how well we are executing on our strategy. With respect to continuing operations, revenue increased 40% year-over-year to $206.5 million, and adjusted net income increased 33% to $51.2 million while adjusted earnings per share increased 47% to $0.75.
In the second quarter, we continue to deliver on the top line. Segment highlights include Carrier Services delivering 14% year-over-year growth, largely driven by NPAC revenue. Enterprise Services also delivering 14% year-over-year growth with contributions from all service offerings including our return to double-digit growth in Internet Infrastructure Services, and Information Services contributing $38 million in the second quarter, representing 6% sequential revenue growth. We're particularly pleased with the strong momentum in new bookings in Information Services, which will support revenue and earnings growth in the business throughout the remainder of 2012 and beyond.
For our business as a whole, we continue to generate the healthy margins that our investors have come to expect, and we continue to return capital to our shareholders through $25 million of stock repurchases. With regard to our next priority, we are well positioned to retain the NPAC contract when the current term expires 3 years from now, that is, at the end of June 2015. We participated in the RFI that was issued by the NAPM LLC in late 2011. We expect the RFP to be issued late in the third or early in the fourth quarter of this year with the contract being awarded in 2013.