Microsoft's offer to license part of its Windows source code to competitors is "not necessarily enough" to head off €2m (about £1.37m) in daily fines for the company, an EC (European Commission) spokesman said today.

Asked whether the move by Microsoft would be enough to bring the company in line with the EC's March 2004 antitrust ruling, Jonathan Todd, spokesman for European competition commissioner Neelie Kroes, said: "It would be premature to conclude access to the source code would resolve the problem of the lack of compliance with our decision."

Yesterday, Microsoft general counsel Brad Smith announced that the company would license source code for communications protocols used by its workgroup server software in an effort to meet the EC’s complaints that Microsoft was still failing to comply with the terms of its antitrust decision.

Smith said yesterday that Microsoft had already complied with the Commission’s demands on server interoperability by providing 12,000 pages of documentation on the protocols.

Todd responded today: "It’s a question of the quality of the information, not the quantity.

"The firm could give us half a million pages, but if it’s not the right information to allow competitors to make Microsoft-compatible workgroup server products it doesn’t solve the problem of compliance."

Microsoft’s offer was instantly dismissed by some of its rivals, who called it a "public-relations ploy" that would inundate developers with useless information.

UK analyst company Ovum also criticised the offer, calling it "superficially appealing".

"There's no doubting that the source code for software represents the most accurate and reliable documentation," Ovum analysts Gary Barnett and David Mitchell wrote in an email to clients. "[However,] source code is of little practical benefit to those trying to develop interoperable code – there is simply too much of it, and it's too hard to understand."

Instead, Microsoft should work with the EC to figure out what's wrong with the technical documentation it has provided, the analysts said.

"This would represent a far more suitable and sincere attempt to bring this saga to a close, rather than adding another dimension to an argument that is already confused," the analysts wrote.

The technical documentation is supposed to help competitors develop products that can interoperate well with Microsoft's dominant Windows software. The EC believes this will help level the playing field for competition.

Click here for the best Microsoft voucher codes.