IBM accounted for 26.9% of worldwide Unix server sales during the fourth quarter of 2001, compared to 26.8% from second-place Sun, IDC said. Hewlett-Packard came in third, with a market share of 25%.
Sun challenged the accuracy of IDC's figures, saying that estimates of Unix server revenue at IBM and HP were inflated. "According to the other source, which is Gartner, we were ahead of IBM in Unix revenue by $600m (£421m) in quarter four," said Shahin Khan, Sun's chief competitive officer.
Nevertheless, Khan acknowledged that IBM has become a more formidable competitor in the Unix server segment. "We used to compete a lot more with HP and now we compete a lot more with IBM," he said.
Overall, the fourth quarter was tough on server vendors, IDC said.
Factory revenues tumbled 26% to $12.6bn (£8.8bn) from $16.9bn (£11.8bn) during the same period a year ago, according to IDC. Unit shipments also declined, falling 7% to 1.1 million units. But the worst may be over for vendors. IDC said the downturn in demand for servers has bottomed out, and companies are starting to once again invest in Internet-related infrastructure.
In the high-end server market, IBM again claimed the top spot with a 28% share of the worldwide market. Compaq came in second with a 16% share, followed by HP in third place with 14.4%.
Overall, IBM took the top spot with a 32% share of worldwide server revenue, IDC said. Trailing IBM in second place was Compaq (17%), followed by HP (14%), Sun (12%) and Dell. (7%).
One notable addition to the list of top server makers is Hong Kong-based Legend Holdings. The company, which mainly operates in China, was the world's tenth-largest provider of server hardware during the fourth quarter, according to IDC.