Worldwide server revenue remained flat at US$12 billion in the first three months of the year, bucking several consecutive quarters of year-on-year growth, research firm Gartner said Tuesday.While revenue remained flat, the total number of servers sold increased, reflecting the continuing shift in spending on lower-end x86 servers. Worldwide shipments increased about 14 percent, from 1.7 million to\u00a02 million in the quarter. Unix server revenue fell about\u00a05 percent, and shipments declined about\u00a01 percent. Blade server shipments, however, were up 46 percent, with IBM leading that market.While IBM maintained its edge over Hewlett-Packard (HP) as the market leader in worldwide server revenue, IBM\u2019s revenue dipped about\u00a04 percent in the quarter. Slower sales of IBM\u2019s Unix, mainframe and minicomputer servers were offset by an 11 percent jump in x86 server revenue.Sun Microsystems meanwhile saw its server revenue rise for the first time in nearly two years, driven by sales of its UltraSparc and Opteron-based servers. And Dell uncharacteristically stumbled a bit in the quarter, with a\u00a02 percent dip in revenue.Dell shipped\u00a07 percent more servers in the quarter at 431,000 units, falling in second place behind HP, which shipped about 538,000. HP\u2019s\u00a08 percent shipment growth was led by a 30 percent increase in shipments of Integrity servers. IBM, which fell in line behind HP and shipped about 299,000 servers in the quarter, saw a 19 percent boost in shipments. Rival research firm IDC, meanwhile, reported Wednesday that based on its research methodology, the worldwide server market declined nearly\u00a02 percent to about $12 billion in the first quarter of 2006 from the same quarter last year.This marked the first quarter of revenue decline after about\u00a010 quarters of year-over-year growth and one quarter of flat growth, in the fourth quarter of 2005, according to IDC\u2019s research.While the x86 server market continued to grow, IDC researchers reported that year-over-year growth slowed to about\u00a06 percent in the first quarter of 2006, compared with 13 percent year-over-year growth in the first quarter of 2005.-Shelley Solheim, IDG News ServiceFor related news coverage, read AMD Winning Commercial Market Share.Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.