Sun Microsystems Inc. regained the No. 3 ranking from Dell Inc. in the market for business server computers in the second quarter as it launched new products, researcher IDC said on Tuesday.

Sun also was the only large computer maker to gain share in the worldwide server market in the second quarter, according to IDC. Dell had usurped the No. 3 position from Sun in the third quarter of 2005 and held it through this year's first quarter.

Sun had 12.9 percent of the worldwide server market in the three months ended June 30 compared with 11.2 percent a year earlier, IDC estimated in its quarterly server market survey.

Sun's server revenue surged 15.5 percent to $1.59 billion in the three-month period, IDC estimated.

Dell slipped to fourth place with 10.3 percent of the market, down from 11.1 percent in the first three months of 2006, IDC estimated. Dell's server revenue slipped 1.3 percent year-over-year to an estimated $1.27 billion, IDC said.

Sun of Santa Clara, California, has been rolling out new products and software under its new chief executive, Jonathan Schwartz, who took over from co-founder Scott McNealy in April.

Revenue growth in Sun's most recent quarter exceeded analysts' average estimates, helped by new servers using Opteron chips from Advanced Micro Devices Inc.

Sun's server business, which returned to growth in the company's fiscal third quarter for the first time in five years, continued growth in the fiscal fourth quarter ended June 30, Sun said last month.

Sun is a standout, said Jean Bozman, research vice president for worldwide server research at IDC. Compared with last year, their server sales were really much stronger. They are accelerating growth.

Besides Dell, other large vendors also had year-over-year market share declines. Market leader International Business Machines Corp.'s (NYSE:IBM - news) share declined to 31 percent from 31.9 percent as revenue slipped 2.2 percent, IDC estimated.

Hewlett-Packard Co.'s (NYSE:HPQ - news) share fell to 27.8 percent from 28.5 percent, giving it the No. 2 spot in market share. HP's server revenue declined 1.7 percent to $3.42 billion, according to IDC.

Overall, worldwide server market revenue grew 0.6 percent in the second quarter to $12.3 billion, led by growth in so-called volume servers costing less than $25,000, IDC said.

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