The judge overseeing the Microsoft Corp. antitrust case on Thursday gave the company and the Justice Department an extra four days to submit a joint report that had been due in court on Friday, the company said.

U.S. District Court Judge Colleen Kollar-Kotelly extended until Tuesday the deadline for a report outlining how both sides think the case should be handled going forward, Microsoft said in a statement.

The two sides had filed a joint request for an extension late Wednesday, Microsoft spokesman Jim Desler said. Desler said he did not know the reason for the request. The Sept. 21 date for a previously scheduled conference with the judge has not changed, he said.

Kollar-Kotelly is to hold hearings in the fall to decide what sanctions should be imposed on the company to prevent future antitrust violations.

On June 28 a federal appeals court upheld a ruling that the company abused its monopoly power to protect its dominance in the market for personal computer operating systems. But it reversed a lower court order to break up the company and directed the district court to hold hearings to determine a proper remedy.