The European Commission will force Microsoft to share technical information about Windows for next to nothing, according to leaked documents.

The commission has been locked in a long-running anti-trust case with the software giant and last month EC attacks Microsoft for using outlawed tactics Microsoft for continuing to gain market share using tactics that were outlawed in a 2004 anti-trust ruling against it.

Under the terms of the anti-trust ruling, Microsoft must license technical information about Windows to other software firms, to ensure they are not unfairly prevented from producing applications that run smoothly with the operating system.

Microsoft is seeking up to 5.95 percent of companies’ server revenues in licence fees. But confidential documents from the commission make clear that Microsoft will be permitted to charge only a tiny fraction of the fees it is demanding, the Financial Times has reported.

The documents seen by the newspaper detail the commission’s objections to Microsoft’s demands. They reveal that the commission’s technical expert, Professor Neil Barrett, has calculated that even an average royalty rate of 1 percent would be unacceptable for licensees.

In the documents, Professor Barrett argues that a 0-percent royalty would be “better” and adds: “We can only conclude on this basis that the Microsoft-proposed royalties are prohibitively high [...] and should be reduced in line with this analysis.”

Rival companies – understood to be IBM, Sun and Oracle – agree with the academic’s findings. “The prices charged by Microsoft are prohibitive and would not allow them to develop products that would be viable from a business perspective,” the commission papers say.

Microsoft said it would respond to the latest statement of objections in full by 23 April. A spokesperson said the company believed it was in compliance with the 2004 commission ruling and that the terms on which it has made the technical data available are “reasonable and non-discriminatory.”

The commission had previously set a 3 April-deadline for Microsoft to respond, but last week the software firm secured an extension until 23 April.