Four MEPs - three of them from the UK - have complained about the European Commission's actions toward Microsoft, claiming it could endanger the competitiveness of European businesses by delaying the release of Windows Vista.

In a letter submitted to competition commissioner Neelie Kroes, the four pointed out that Microsoft regards the EU's regulatory actions as a "risk factor" - the terminology that Microsoft used in its annual report filed to the US Securities and Exchange Commission a fortnight ago.

"This effectively means that the Commission's actions are endangering the ability of European business to compete globally," the legislators wrote. The letter is signed by UK representatives Chris Heaton-Harris, Sharon Bowles and Peter Skinner plus Michal Kaminski of Poland.

Heaton-Harris is an advocate of Microsoft, complaining about the EC's actions against the software giant in the past, and even meeting Microsoft CEO Steve Ballmer at Microsoft's HQ last month.

Microsoft wrote in its SEC filing that its ongoing appeal of European Commission's March 2004 anti-trust decision means there's uncertainty over the legal principles regarding product design in the European market. "These uncertainties could... delay release dates for Windows or other products," the SEC filing read.

Microsoft has provided copies of Vista to the Commission along with technical information, said a company spokesman. The Commission, he said, has raised concerns regarding complaints by competitors. In March, the Commission sent a letter to Microsoft CEO Steve Ballmer, saying it was concerned about certain functions in Vista and how compatible the OS would be with products from other software companies.

Microsoft was unaware of the MEP letter until this morning, the company claimed. Two of the legislators said their letter was based on information contained in the company's SEC filing.

Heaton-Harris referred questions to Microsoft, regarding why the company thought the EU might cause a delay Vista's shipping date. Bowles said she has participated in informal sessions where Commission members have acknowledged they are watching Microsoft's development of Vista closely. She said she had no specific information on what the Commission is currently doing, as few details are publicly released.

However, the letter argued, the Commission's actions had prompted concern among businesses in Europe that the EU could potentially delay Vista's European release, putting them at a competitive disadvantage with the rest of the world. "That climate of uncertainty caused through competition policy and actions already taken ... are meaning that Europe is being deprived," Bowles said.

The EC fined Microsoft an additional €280.5 million on top of its original €497 million in July for failing to provide technical documentation for certain protocols used by its server products. The Commission required disclosure of the protocols to allow competitors to develop compatible products. Microsoft is appealing.

A Commission spokesman rejected the assertions made in the letter. "There is no reason why Microsoft cannot market Vista in a way that is fully compliant with competition regulations," he said.