Microsoft will sell Internet Explorer without a browser in Europe, in an effort to avoid further anti-trust action by the European Commission.

The move stems from a complaint that  browser developer Opera filed with the European Commission in 2007 saying that Microsoft gets an unfair advantage by tying IE with Windows; Mozilla has joined Opera in the suit. By shipping Windows 7 without the browser, Microsoft may avoid potential requirements to delay shipment or other sanctions.

"We're committed to launching Windows 7 on time in Europe, so we need to address the legal realities in Europe, including the risk of large fines," Dave Heiner, deputy general counsel at Microsoft, wrote in a blog post on Thursday.

PC makers and distributors will be able to add any browser to the Windows 7 machines and Microsoft said it planned to make it easy for them to do so.

While the company believes that most people will buy Windows 7 as part of a new computer, some will surely buy the software in order to upgrade an existing machine. "They will be able to add the browser of their choice via CD distribution, FTP installation, retail distribution or other means," a Microsoft spokesman said.

In addition, Microsoft plans to ship the Windows 7 Internet Pack, a free DVD that will include Internet Explorer 8 for Windows 7 and Windows Live Essentials. The DVD will be available via retail, FTP and other channels, the spokesman said.

Even though Microsoft says it will make it easy for PC makers and users to get IE, a version of Windows minus IE is a good opening for competitors to try to persuade PC makers to put their browsers on computers. Google, for example, could use this as an opportunity to try to get its Chrome browser to a substantially larger user base, especially in Europe where Google's search share is even bigger than it is in the US, said Matt Rosoff, an analyst with Directions on Microsoft.

"If they can spend however many billion or million to get every PC in Europe to go out with Chrome as the exclusive browser, suddenly people will use Chrome a lot more," he said.

Microsoft warned that this move does not necessarily spell the end of the Commission's investigation. "Our decision to only offer IE separately from Windows 7 in Europe cannot, of course, preclude the possibility of alternative approaches emerging through Commission processes," Heiner wrote.

During commission proceedings, other alternatives have come up, such as requiring a screen in Windows 7 that would let users choose from a variety of browsers. "Important details of these approaches would need to be worked out in coordination with the Commission, since they would have a significant impact on computer manufacturers and web browser vendors, whose interests may differ. Given the complexity and competing interests, we don't believe it would be best for us to adopt such an approach unilaterally," he wrote.

Such a requirement would indeed by burdensome for Microsoft, Rosoff said. "It would force Microsoft to enter into a lot of negotiations to make sure these browsers were supported correctly and would complicate support for Microsoft and the OEMs," he said. "They figured they would take the hit and unbundle it entirely and if people want it, they know how to get it."

The EC's browser case follows a landmark anti-trust ruling against Microsoft in 2004. Part of that case dealt with the bundling, or tying, of Media Player to the Windows OS.