IBM's third-quarter revenue met expectations as corporate spending on information technology held up in the face of economic worries and the company bumped up its 2011 earnings outlook.

U.S. economic concerns and a worsening European financial crisis have hurt consumer demand, but companies like IBM that sell hardware and software for giant data centers powering the Internet have benefited from resilient enterprise spending.

IBM said full-year diluted earnings would be at least $13.35 per share, up from a prior prediction of at least $13.25 in July.

But recently strong shares in the Armonk, New York, company fell 2.46 percent to $182 in extended trade after closing down 2.07 percent on the New York Stock Exchange.

Signings in the quarter were $12.3 billion, in line with some analysts expectations of between $12 billion and $13 billion.

Revenue rose 8 percent from a year earlier to $26.2 billion, in line with the average forecast of $26.26 billion, according to Thomson Reuters I/B/E/S.

International Business Machines reported third-quarter profit, excluding items, of $3.28 per share, up 15 percent year over year.

(Reporting by Noel Randewich)