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What: Shares of ACI Worldwide (NASDAQ:ACIW) have skyrocketed today by as much as 17% after the company reported earnings and reaffirmed guidance.

So what: Revenue in the quarter totaled $155.1 million, an increase of 38% over last year, although more than all of this gain was attributed to the acquisition of S1. Earnings per share was $0.29, which was slightly worse than the $0.31 per share profit that the Street was targeting.

Now what: The company reaffirmed full-year guidance, expecting adjusted revenue to be in the range of $706 million to $716 million, and adjusted EBITDA of $188 million to $193 million. On a GAAP basis, 2012 should see sales of $683 million to $693 million. During the quarter, ACI also completed its acquisition of Distra, which will provide additional cross-selling opportunities.

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