Amazon.com gave a just-hired former Microsoft executive stock incentives worth more than $12.8 million, the Seattle-based online retailer disclosed Wednesday.

The stock award, which was filed with the Securities and Exchange Commission (SEC), gives 400,000 shares to Brian Valentine, who when he recently resigned from Microsoft had headed Windows Vista development. Valentine, a 19-year veteran of Microsoft, had been blamed for Vista's delays, some analysts have said; last month, Microsoft announced that he would be reassigned as soon as Vista was shipped, and the unit handed over to another senior vice president, Jon DeVaan.

Amazon's SEC filing said that Valentine's 400,000 shares would be vested between September 2008 and September 2012 at a rate of 20 percent annually as long as he's with the company. As of Thursday, Amazon shares were trading at $32.06, which would peg the incentive's current value at approximately $12.82 million.

Valentine is only one of several high-profile Microsoft executives and managers who have left the Redmond, Wash. developer recently. Last week, John Lauer, a vice president in Microsoft's Small and Midsize Solutions & Partner Group, said he was leaving to launch a CRM startup.

In June, Bill Gates said he would step down as the company's chief software architect in two years. Ray Ozzie, currently Microsoft's chief technical officer, will take his place while Steve Ballmer remains chief executive.