June 20 (Bloomberg) -- Microsoft Corp. said Martin Taylor, a protégé of Chief Executive Officer Steve Ballmer who was promoted to vice president in March to revamp marketing for the MSN Web sites and Windows Live services, has left the company.

``We've made the difficult decision to part ways with Martin Taylor but we don't comment on personnel matters,'' the company said in an e-mailed statement that didn't disclose the reason for his departure. Adam Sohn, a director in the group that reported to Taylor, declined to comment.

Taylor is credited with helping Microsoft beat back the threat posed by the free Linux operating system when he was head of platform strategy with the Windows group. His exit leaves Microsoft searching for a new marketing expert to anchor the company's efforts to win customers from Google Inc.

``This is a problem because this is supposed to be the big marketing thrust for Windows Live,'' said Paul DeGroot, an analyst at Kirkland, Washington-based market research firm Directions on Microsoft. ``It's important that they get the brand out and that they have somebody in that position that has the confidence of senior management and can get things done.''

As recently as March 23, when Microsoft promoted Taylor, 36, analysts praised him for his prowess in resolving tough issues. Rob Enderle, an analyst at San Jose, California-based researcher Enderle Group, said Taylor was becoming ``a go-to guy for problem areas.''

Taylor, a 13-year veteran of Microsoft, was also close with Ballmer, 50, joining in Ballmer's Wednesday morning basketball game and spending 18 months working directly for him on improving Microsoft's customer service.

``He was the fair-haired boy,'' Enderle said today.

Quoted Yesterday

Taylor was quoted in a Microsoft news release yesterday about the new Windows Live instant messaging service and was slated to talk with reporters about the product. Interviews were instead handled by Sohn because of what the company said yesterday was a scheduling conflict.

Two phone messages left at the phone number listed for Taylor's Renton, Washington, house weren't returned.

Shares of Redmond, Washington-based Microsoft rose 1 cent to $22.56 as of 4 p.m. New York time in Nasdaq Stock Market composite trading. The shares have declined 14 percent this year.

The departure comes as Microsoft embarks on a series of Windows Live product releases to make up ground lost to Google and Yahoo Inc. in Internet-based services. Yesterday's introduction of the new instant messaging product marked the first of 17 services that are slated to be finalized this year.

Microsoft has added about $2 billion in spending in the year that begins July 1, largely to fund its Internet efforts. Google, owner of the world's biggest search engine, has almost five times as many users for its Internet search as Microsoft in the U.S.

Anti-Linux

Prior to taking a job as Ballmer's director of business strategy in 2001, Taylor held a number of sales positions at Microsoft.

As head of Microsoft's anti-Linux strategies from 2003 until March, Taylor tried to move away from the acrimonious rivalry that had Ballmer calling Linux a ``cancer'' and toward an approach in which his team assembled facts and examples to sway customers. Taylor worked to show Microsoft's Windows was superior to Linux in areas such as security and cost, and funded studies by third parties that defended Windows.

Taylor also tried to meet with Linux devotees and hired experts from the Linux world, such as a salesman who won a key Linux contract over Microsoft and an International Business Machines Corp. Linux executive. In 2004, he showed up at the LinuxWorld conference wearing a flak jacket and took questions from attendees.

To contact the reporter on this story: Dina Bass in Seattle at Dbass2@bloomberg.net.

Last Updated: June 20, 2006 19:08 EDT