Microsoft fined €900 million by Brussels

Competition commissioner Neelie Kroes sharply criticised the company when making the announcement, pointing out it was the third time in four years the commission has charged the firm for antitrust violations.

"Talk is cheap; flouting the rules is expensive. We don't want talk and promises – we want compliance.

"If you flout the rule, you will be caught, and it will cost you dear."

The fine comes on top of the original penalty levied in 2004 of €497million.

The 2004 decision, later upheld in 2007 by the Court of First Instance, found that Microsoft had abused its dominant position in the market, and ordered the company to disclose interface documentation to other firms a reasonable price.

The penalty only covers the period from the 2004 ruling to 22 October, 2007. Initially charging a 2.98 percent fee for the information, from October, 2007, Microsoft last year started to provide a licence giving access for a flat fee of €10,000 and an optional worldwide patent licence for a royalty of 0.4 percent of a company's product revenues.

The fine does not however cover the company's other business practices, the commissioner stressed.

The commission opened two other antitrust inquiries last month looking at a number of the company's other activities, including concerns surround the Office suite of programmes, its server products and the bundling of its internet brower, Internet Explorer, with Windows.

Ms Kroes' speech to the press critical of the company's scofflaw attitude.

"Finally, after three years of illegal behaviour, it appears that Microsoft has come into compliance with the 2004 decision," she said.

Meanwhile, Microsoft on Wednesday is launching its Windows Server 2008 product.