We have established 3 key enterprise priorities to help you better gauge our current performance and strategic progress in 2012. First, to deliver an increased level of high-quality revenue growth and meet our earnings commitments. Next, to center the Fiserv culture on growth, leading to more clients, deeper relationships and a larger share of our strategic solutions. And third, to deliver innovation that increases differentiation and enhances results for our clients. Adjusted internal revenue growth of 4% matched our strong fourth quarter performance and accelerated from 3% in the first quarter of 2011. Growth in the quarter was driven by recurring revenue in our Debit and Account Processing businesses, along with solid performance across our digital channels, reflecting strong demand for mobile banking solutions and the industry's renewed focus on Online Banking.
Adjusted operating income was up 6% in the quarter, leading to higher operating margin and another quarter of double-digit adjusted EPS growth. Strengthening the foundation of our growth culture leads to better results now and into the future. We are executing against our go-to-market strategy, which is well aligned with technology and consumer trends.
As proof points of the market demand, we signed a combined 230 Payments clients to our bill payment, debit and P2P solutions in the quarter, and nearly 150 clients selected our market-leading mobile solution. We also had 2 additional large credit unions commit to Acumen, our next-generation account processing platform in the quarter. We remain encouraged by the strong interest in this advanced technology platform, and as important, the significant number of additional solutions that are being purchased along with the core.
Last week, we hosted over 3,600 attendees at our 2012 spring client event, Fiserv Forum. This event will end up being one of the largest gatherings of financial institution executives in the U.S. this year. In addition to having marquee speakers such as President Bill Clinton and Dr. Fareed Zakaria, we had strategy sessions, product forums and user groups. We also hosted a 70,000 square-foot solution center showcasing more than 100 of our leading technology solutions geared at driving a broad range of value for our clients. The feedback on the event has been outstanding.Read the rest of this transcript for free on seekingalpha.com