Kevin Browne, who has headed Microsoft's Macintosh Business Unit (MacBU) for the past three years and has been onsince July, is moving to an unspecified role in the company's Xbox unit.
"At the end of October, he will transition to a new challenge building games for xBox," a Microsoft representative said in an e-mail to CNET News.com. "This new job offers Kevin the opportunity to learn new skills, work with a group of customers who are extremely passionate about great software (just like Mac users), and pursue his personal interests in games and sports."
Browne, who joined the Mac unit six years ago, was scheduled to return to the MacBU this month.
Microsoft said it is in the process of determining who will fill the top MacBU position. In the meantime, the unit will be led by the three executives who ran the division while Browne was on sabbatical.
In the days before he went on leave, Browne was critical of Apple's efforts to promote Mac OS X and noted that sales of Office for Mac OS X had fallen short of the Microsoft's expectations.
Microsoft has recently tried to put a positive spin on the situation, including launching awith Apple to discount the $500 price of Office for new Mac purchasers and a new ad campaign.
A five-year deal between Apple and Microsoft that required the software giant to develop Mac versions of Office and Internet Explorer recently ended. Microsoft hasits support for the Mac but has said it will only commit to new software updates one version at a time.