International Business Machines Corp. (IBM) said Wednesday its first-quarter net income rose 15 percent, and the world's largest computer maker said it expected to outperform its rivals but was not immune to customer spending cutbacks.

The company, based in Armonk, N.Y., reported net income of $1.75 billion, or 98 cents per share, compared with $1.52 billion, or 83 cents per share, a year earlier. Analysts had expected earnings in a range of 89 cents to $1.02, with the average at 98 cents.

Sales rose 9 percent to $21 billion in the quarter.

The report came after the close of the regular trading session. IBM shares closed up $6.80, or 6.8 percent, at $106.50 on the New York Stock Exchange. The stock has outperformed the S&P 500 index by about 30 percent this year.

"Looking forward, we are no better than others in predicting how the current economic uncertainty will unfold," Chairman and Chief Executive Louis Gerstner said in a statement.

"IBM is certainly to not immune to broad cutbacks in customer spending. However, based on recent results, we expect we will outperform most of our competitors in whatever market emerges this year."

IBM's view of the year ahead is regarded as an indicator of what to expect for the rest of the year for the tech sector and the stock market at large.

Its stock has been seen as a safe haven for tech investors for its wide base of products that range from custom microchips to supercomputers. The company has sidestepped the brunt of a tech downturn in part on the strength of an upgrade of its mainframe computers and expanding microelectronics business