REDMOND, Washington: Christopher Payne, vp of Microsoft's Windows Live Search group, is leaving the software titan to start his own Seattle-based company, say insiders. It is not known if his departure is voluntary.

Payne's exit reflects a number of changes made by svp Steve Berkowitz, hired last year from search engine to head Microsoft's online group. Earlier this week Berkowitz appointed three new [unnamed] marketing managers to his cadre, one of whom is responsible for search marketing.

According to NetRatings, Microsoft's share of the US search market was just 8.9% in January, a mere 2.5% up on the year-ago period.

Google, by contrast, processed 40.6% more queries over the same period to attain a 53.7% market share. In the overall US search market Microsoft lags third behind Google and Yahoo.

Another seeming casualty of Microsoft's failure to make adequate progress within the search market is vp Blake Irving, responsible for its AdCenter. He will 'retire' this summer.

Data sourced from Wall Street Journal Online. additional content by WARC staff