US state lawmakers are being pressed by an industry trade group, created by Microsoft's biggest foes, to file a second antitrust suit against the Washington software maker.

ProComp, a group backed by Microsoft rivals including Oracle and Sun Microsystems, took paperwork to Vermont Wednesday. The companies are trying to convince US state attorneys general that Microsoft's plans to bundle messaging and media applications with its next operating system is a move to extend its monopoly into other markets.

The group suggested that Microsoft is again using its monopoly power in the PC-operating-systems market to stifle competition, this time with its forthcoming Windows XP operating system, said ProComp president Mike Pettit.

Further meeting He would not comment on whether the state attorneys general were receptive to his presentation, but noted he would likely return to their meeting Thursday to answer more questions.

He added: "I'm not in the position to summarize their response. Those are judgements they have to make on their own."

Attorneys general attending the meeting could not be reached for comment, but Iowa Attorney General Tom Miller told the Associated Press that the states are concerned that Microsoft's strategy with Windows XP may be harmful to competition.

Miller claimed: "Microsoft seems to be using much of its power to preclude competition on a new platform. This is what they did before, and this is what they're doing again to maintain their monopoly."

Similar strategy Part of Microsoft's strategy with Windows XP parallels the one used in 1996 when it tightly integrated its Internet Explorer (IE) Web browser with Windows, Pettit said. By giving its browser software away for free with the operating system, which was used on almost 90 per cent of all PCs, Microsoft helped crush a competing browser from Netscape Communications. The behaviour, described in an antitrust suit filed by the US department of Justice and 19 state attorneys general, contributed to the company being branded a predatory monopolist by a US District Court, a decision the software maker has appealed.

Jim Cullinan, a spokesperson for Microsoft, said of ProComp's visit to Vermont: "It's disappointing, but not surprising, that our competition continues to use time and resources to press law makers rather than innovate."

But other critics besides Microsoft's industry rivals share scepticism over Microsoft's strategy to bundle new applications with its operating system. Analysts have expressed similar concerns over the software maker's use of Windows XP and its emerging .Net initiative to threaten competition in various markets.

"There are shades of IE" in Microsoft's Windows XP strategy, said Charles King, an analyst with Zona Research in Redwood City, California. He added: "It does raise the spectre again as to what constitutes an operating system."