ACI Worldwide Inc. reported on Tuesday that income for the fourth-quarter was $23.9 million, down 11.8% from a year earlier, as revenue declined.

The New York company also reported that income for 2011 climbed 69% to $45.9 million.

Fourth-quarter revenue declined 4%, to $135 million, from a year earlier as fewer projects moved out of backlog. Revenue for 2011 rose 11%, to $465.1 million.

The company reported that sales bookings in the quarter totaled $171.4 million, down 2% from a year earlier. Fourth-quarter operating expenses declined less than 1%, to $98 million but rose 9%, to $398.9 million, for the year. The increased expenses for the year related to higher sales and marketing expenses and greater research and development expenses.

ACI also said that it closed its acquisition of S1 Corp. in Norcross, Ga., on Friday. ACI bought the technology vendor for roughly $360 million in cash and 5.9 million shares for a total value of $569 million.