A top European Union judge challenged the EU executive's reasoning in its antitrust court battle with Microsoft yesterday, questioning why it opposed the US software giant's setting industry standards.

Mr Bo Vesterdorf, president of the European Union's Court of First Instance, threw down the challenge during the second day of hearings on Microsoft's request to suspend penalties levied on it while it pursues an appeal that could take years.

At the end of the day, Mr Vesterdorf said he would decide soon whether to freeze the penalties.

The EU decision requires that Microsoft sell a version of Windows without audiovisual software and forces it to provide information so rival makers of servers can compete more easily.

The Commission found in March that Microsoft abused its operating system monopoly to hurt competitors. Microsoft, which must show "irreparable harm" to overturn that finding, says offering a degraded system would damage its good name.

Earlier, the Commission said Windows Media Player was near a "tipping point" in usage that would cripple rivals such as RealPlayer in the same way that Microsoft illegally wrested away the Web Browser market from Netscape in the 1990s.

Microsoft lawyer Mr Jean-Francois Bellis said Microsoft should not be forced to break its flagship product into fragments.

"It strikes at the very heart of Microsoft's business model and design of Windows."

RealNetworks presented a demonstration showing Windows would work even without a media player, but Microsoft showed video demonstrating Windows would "break" in that situation, with media files not playing properly.

Mr Vesterdorf said on Thursday that he believed it was possible Microsoft could win when the main case finishes years from now.