IBM ( IBM) has slipped ahead of BEA Systems ( BEAS) and now holds the largest share of revenue in the Java-based application server market.

A new report by researcher Gartner Dataquest shows that IBM's WebSphere application server had 37% of the market in 2002, while long-term leader BEA was in second place with 29%. In 2001, BEA led with a share of 34% vs. IBM's 31%. Application servers are software that allows enterprise applications to use data from a variety of databases.

"The tight horse race that started in 2000 between IBM and BEA was won in 2002 by IBM as they continued to gain market share in all categories," said Gartner analyst Joanne Correia, who presented the study at an industry conference this week. "IBM gained market share of new-license revenue at the expense of BEA and others.

Some analysts are skeptical -- as was a BEA spokeswoman Tuesday. If true, though, the news is a blow to BEA, which derives more revenue from its WebLogic application server than any other product.

With one exception, the company does not break out revenue by product. That exception is the company's integration server, which in the January quarter contributed $20 million, or about 15% of overall license revenue.

Integration server sales are significant because BEA acknowledges that the market for application servers is no longer a fast-growing one, and it is making a bet that the integration server (and other platform components) will drive growth in the future.

BEA, a relatively new player in the integration market, did not show up on Gartner's list of the top 5 integration vendors, while IBM leads with an estimated share of 17.4%. However, BEA "is gaining momentum in the integration market," said Correia.

IBM also led in the so-called application platform suite category (which includes application and integration servers as well as some other components) with 20% of the market, compared to 11% for BEA and 5% for Oracle ( ORCL). The platform market is significant because many enterprises are moving toward reducing the number of technology vendors they utilize for critical applications, and a broad platform is seen as a way to win that business.

No matter who comes out on top, market share numbers are frequently challenged, and this report is no exception.

A number of sell-side analysts published notes downplaying the survey, including Brendan Barnicle of Pacific Crest Securities. Barnicle said the Gartner app server report was inconsistent with his own research showing that there has not been a significant shift from BEA to IBM. Moreover, Barnicle said that different companies report sales in different formats, making head-to-head comparisons very difficult. (Pacific Crest does not have a banking relationship with BEA.)