International Business Machines Corp. (NYSE: IBM), the No. 2 computer maker, boosted its full-year net earnings estimates to at least $14.40 a share from the previous estimate of $14.27.

The Armonk, N.Y. company said on an operating basis, full-year earnings could be $15.10, compared with the prior estimate of $15.00.

In 2011, IBM reported net income of $15.85 billion or a record $13.06 a share.

The company reported second-quarter net income rose 6 percent to $3.9 billion, or $3.34 a share, despite a drop of 3 percent in revenue to $25.8 billion. The earnings exceeded estimates whereas revenue growth was slightly below.

Shares of IBM rose $3.75 or 2 percent, to $192 in after-hours trading.