NORTH CHICAGO – Abbott Laboratories' second-quarter net income fell 11 percent but its adjusted earnings narrowly beat Wall Street estimates as sales of its blockbuster anti-inflammatory drug Humira increased 23 percent.

Last fall, Abbott surprised investors and analysts with the announcement that it would spin off its branded drug business, including Humira, before the end of 2012.

The split-up would free Abbott from the risks and obligations of developing innovative pharmaceutical drugs, leaving the company with a more predictable business built around nutritional formula, generic drugs and heart stents.