The European Commission has threatened Microsoft with daily fines of €3 million ($3.8 million) if it doesn't provide interoperability information about its Windows operating system by November 23.

This is the latest in a string of deadlines imposed over the past two years in an effort to get Microsoft to license technical documentation for Windows that would allow rivals to develop server software programs to interoperate with PCs running Windows.

"The Commission expects the remaining omissions and deficiencies in the technical documentation to be remedied by November 23 so that by the end of November the entire set of technical documentation will be available for potential licensees to review," the Commission said.

The order to reveal the documentation was part of the Commission's March 2004 anti-trust ruling against Microsoft, under which it also find Microsoft €497 million. In July this year, the Commission fined Microsoft a further €280.5 million for failing to submit the information.

Competition Commissioner Neelie Kroes repeated her frustrations in an interview published in British newspaper The Guardian. "I am not impressed if someone says 90 percent of the information is already there when we need 100 percent. It's a jigsaw and some parts are missing. ... In my opinion, this information should have been here a couple of months ago," the newspaper quoted her as saying.

Microsoft issued a statement Wednesday, but avoided commenting on the imposition of a new deadline. "Microsoft is committed to full compliance with the Commission's March 2004 decision and we are working closely with the Commission and the Monitoring Trustee towards that goal," it said.

Microsoft initially claimed that it didn't understand what information the Commission wanted. The 2004 ruling ordered the firm to make available enough information about Windows to allow makers of rival server software programs to design their products to work as seamlessly with Windows as Microsoft's own server operating system.

After a hearing earlier this year, Microsoft said it finally understood what the Commission was after, and submitted what it said was the final instalment of information on July 19.

Since then the Commission has been examining the documentation together with the monitoring trustee, Neil Barrett, who was picked by Microsoft to oversee its compliance with the 2004 ruling.

"As of today, the Commission has not received the complete documentation regarding all relevant protocols that is required to comply with its March 2004 Decision," the Commission said Wednesday.

Commission competition spokesman Jonathan Todd said in a news conference that near compliance wasn’t good enough. "Until we have the whole set of documents, what they have provided is worth nothing," he said.

Todd wouldn't say whether failure to meet next week's deadline would automatically trigger new fines.