US Government lobbied EU Commissioner on Microsoft's behalf

The US embassy in Brussels contacted Kroes just before she was to decide what fine to impose on Microsoft in an ongoing antitrust battle with the company. The embassy asked her to be "nicer" to the world's biggest software company. Kroes went ahead and fined Microsoft €280.5 million in July.

The EU's dispute with Microsoft centres on a 2004 antitrust ruling which said that by bundling software with its windows operating system and keeping source code secret, Microsoft was behaving anti-competitively. The fine in July related to Microsoft's alleged failure to comply with the antitrust ruling, which itself had carried a fine of €497 million.

"I believe [the US] intervened in a responsibility which was on our shoulders at that time," Kroes told Dutch newspaper Het Financieele Dagblad. "I said I did not want…an intervention that is not done."

"I am not interested in what nationality a company has, or what size. What is of interest to me is whether [a firm] sticks to the rules. Microsoft is not above the law," Kroes said.

The European Commission and Microsoft are now at loggerheads over the next major Microsoft release, Vista. Kroes had written to Microsoft earlier this year expressing concerns about various aspects of the new operating system.

She said that its integrated internet search facility and its ability to create documents in fixed formats could cause similar competition concerns. Microsoft retaliated by claiming that Commission meddling could result in the release of Vista in Europe being delayed for longer than in other territories. Though Vista is not under formal scrutiny, Kroes's actions demonstrate that problems with it could emerge.

Microsoft said that the Commission's concerns could delay the system and that the Commission had not given it guidance on how it could make sure that Vista did not break the rules. The launch date for Vista was the second half of this year but it has already been delayed.