Microsoft Corp. is dismissing as "a lot of irrelevant background noise" what the government describes as new evidence that the company acted illegally toward some of its most powerful high-tech rivals.

In a 49-page court filing Tuesday, Microsoft sought to buttress its previous request that the federal judge in the government's landmark antitrust case throw out the lawsuit, or at least dismiss crucial parts of it.A hearing is set for Friday.

The $14 billion software company said it is confident it can win a narrowly defined case that focuses on its decision to bundle its Internet browser with Windows.

The government contends that's illegal "tying" under federal antitrust law because it forces customers who use Windows also to use Microsoft's browser, rather than a competitor's browser.

But Microsoft complained that the Justice Department and 20 states suing the company are trying to broaden the case inappropriately by adding new evidence about high-level meetings with executives from Apple Computer, Intel Corp. and others.

"By trying to rewrite and expand their case in the past month, the government has shown a lack of faith in the case they filed last May, after nearly two years of investigation," said Bill Neukom, Microsoft's senior vice president for law and corporate affairs.