The papers will summarize each side's version of the facts of the case.

Judge Thomas Penfield Jackson has then given Microsoft and the Department of Justice one month to study each other's documents and come back to him with any changes.

After final courtroom arguments, he will then give his ruling, probably late this year, but possibly not until early in 2000.

Settlement unlikely

There is still a possibility that an out-of-court settlement could be reached. The sides have met several times since the trial began in October, but observers think it unlikely that they will come to an agreement.

Microsoft is accused of illegally using monopoly power in the software industry to crush potential rivals.

It is likely to argue in its court filing this week that there has been no evidence that its actions have hurt consumers, which would have to be proved to support a guilty verdict.

Netscape has now been bought by AOL - evidence, says Microsoft, of how competitive the market is

It is also essential to prove that a company wields monopoly power, which Microsoft disputes. It will argue that it did not illegally discourage computer makers and Internet providers from using Web browsers made by its rival Netscape.

And it will maintain that America Online's purchase of Netscape demonstrates how competitive the market is.

The government contends that Microsoft does hold monopoly power, and that computer makers and the public have no mainstream operating system alternative and must accept its prices.

It claims the company choked off Netscape's avenues of distribution.