Microsoft Corp. will stop developing a version of its Windows Media Player for Apple Computer Inc.'s Macs, and will instead offer free technology that lets people play Windows Media files using Apple's own software.

The company decided to stop developing the Mac version so it could focus on efforts for Vista, the new version of Microsoft's Windows operating system that is due out later this year, said Tim Harader, a senior business development manager with Microsoft's Windows digital media division.

"We've been so focused on Vista and we've been so focused on creating an incredible media experience on the PC," Harader said Friday. "We just did not have the resources to do a good job on [the Mac version]."

Apple computers represent about 4 percent of the U.S. market. PCs running Microsoft's Windows operating system comprise the vast majority.

Microsoft said it would continue to offer the current version but won't make any more improvements to it. The software maker has signed a deal with Nevada City, Calif.-based Telestream Inc. to offer a free plug-in that will let people play Windows Media video and audio files using Apple's QuickTime player.

Because Microsoft's media player for Macs has not been updated for quite some time, Harader said the quality of some Windows Media files could be better if people used the plug-in and QuickTime.

In 2003, Microsoft also said it would stop making a version of its Internet Explorer browser for Macs.

But just days ago, Microsoft said it had signed a five-year pact with Apple to continue to develop versions of its Office business software for Macs. The company said the deal was partly to show customers that it has a long-term commitment to the Mac market.

Unlike the free Web browser and media player, Microsoft's Office software for Mac sells for between $149 and $499.

Apple declined to comment.