District Judge Thomas Penfield Jackson has asked the Department of Justice to return new proposals for breaking Microsoft up into three separate companies by Friday.

Microsoft pleaded for more time to submit a defence, but Jackson gave the software company just 48 hours to file a response.

"It seems clear the judge was very supportive of the government's claims for a significant remedy," Daniel Rubinfeld, a professor of law and economics at the University of California, said. "The talk now seems to be not whether there is a break-up, but what form it will take."

Impressed Earlier in the day, Jackson referred to a friend-of-the-court brief filed by the Software & Information Industry Association (SIAA) and the Computer & Communications Industry Association (CCIA). The associations advocated the break-up of Microsoft into an operating systems company, an applications company and an Internet company. Jackson characterized it as an "excellent brief".

Rubinfeld said: "The judge's job is to find the best appropriate remedy in light of the harm caused. He could say he doesn't like any of the proposals."

In fact, Jackson said he wondered why the DOJ had not recommended creating three, instead of two, new companies from Microsoft, saying the DOJ proposal might merely result in two separate monopolies.

One industry analyst said the separation of the software giant's Internet business would be a positive step toward ending Microsoft's monopoly.