NEW YORK (AP) - Shane Kim, the Microsoft Corp. executive who oversaw the growth of its video game business from the original Xbox and through such hits as "Halo" and "Gears of War," is retiring after 19 years with the software maker.

Kim, 47, spent 14 of those years with Microsoft's Interactive Entertainment business. In a memo to staff Monday, Don Mattrick, the unit's senior vice president, called Kim an "instrumental leader" in the evolution of the company's games business.

Before leaving at the end of the year, Kim will transfer his duties to Dennis Durkin, who was named to the new post of chief operating officer of the company's video game unit. Another executive, Phil Spencer, will oversee Microsoft Game Studios.

The company did not say what Kim's post-Microsoft plans are other than that he wants to spend more time with family and friends.

Microsoft cut the price of the Xbox 360 last month, in a push to boost holiday sales of the console and corresponding games. Its "Project Natal" motion controller device, which was unveiled this summer and eliminates game controllers, is expected to launch late next year.

Redmond, Wash.-based Microsoft has so far sold more of the Xbox 360 machines globally than rival Sony Corp. did of the PlayStation 3, though both have lagged behind Nintendo Co.'s Wii.