The European Commission yesterday declined to comment on the latest twist in the US case against Microsoft in which the US Department of Justice and state attorneys-general said they will not seek to break up the company. But an official at the competition office of the EU's executive body said the Europe case is "factually and legally different" from the one being conducted in the US.

The US Department of Justice and state attorneys-general informed Microsoft that they will not seek a break up of the company and will not pursue the issue of whether the software maker illegally tied its Internet Explorer browser to the Windows operating system.

Last week, the EC combined two separate antitrust investigations into Microsoft and added new accusations that, by bundling its Media Player music and video streaming software with Windows, the company is abusing its dominant position.

The new strand in the EU case bears a resemblance to the abandoned US claim that Microsoft bundled, comingled, IE with Windows. There was no cooperation between the two authorities [the DoJ and EU] on that matter, said the EU’s competition office spokesman, who asked not to be named. "In merger rulings there is closer cooperation, but with antitrust there are limits to the amount of cooperation, such as exchanging information," he said.

Exchanging sensitive corporate information between regulators requires the permission of the companies involved. John Frank, Microsoft senior corporate attorney in Europe, said the company has not been asked for such permission.

In 1994, the European Commission and the DoJ jointly forced Microsoft to abandon its licensing agreements with PC makers, which forced them to pay a royalty on every PC whether or not Microsoft software was preinstalled on it. At the time the EC hailed the joint ruling as a model of how to tackle giant companies and Microsoft said cooperation was "helpful".