Symantec has made a complaint against Microsoft to EC anti-trust regulators over the software giant's entry into the security market.

The "informal" complaint allows the Commission to consider whether or not an anti-trust case is merited. The Commission is the executive branch of the European Union (EU).

The news comes on the day Microsoft announced plans to begin offering business users an integrated anti-virus and anti-spyware product called Microsoft Client Protection. A beta version of this product is expected to be released by year's end. The company is already offering some customers a beta version of its Windows OneCare consumer security software.

At issue is Microsoft's plan to bundle its security software with Windows Vista, the next major version of the Windows operating system due next year.

A Symantec spokeswoman said the company had not filed a formal complaint, but added: "We have been asked to provide information to the EU, and we have complied with that request. The information was really helping them understand the complexity of the security industry and our role in it."

Shortly after Microsoft announced its intention to enter the security space, Symantec CEO John Thompson hinted the company was considering an anti-trust complaint: "They can't use their Windows monopoly unfairly, and the world will be watching. And we will as well."

Last year, the Commission ordered Microsoft to pay €497 million and to ship a versions of its operating system that did not include the Windows Media Player, ending a five-year anti-trust investigation into the company.