Former Yahoo man Dr. Qi Lu will join the Redmond company as president of the Online Services Group and will be in charge Microsoft’s search and online advertising initiatives, as well as the company’s online information and communications services.

Previously, Lu, was an executive vice president of Engineering for the Search and Advertising Technology Group at Yahoo and was responsible for the company’s search, e-commerce, and local listings of businesses and products. Lu has been with Yahoo for over 10 years.

Lu will start at Microsoft on January 5, 2009 and will report to Microsoft Chief Executive Officer Steve Ballmer.

“I am tremendously excited to welcome Qi to Microsoft,” Ballmer said. “Dr. Lu’s deep technical expertise, leadership capabilities and hard-working mentality are well-known in the technology industry, and Microsoft will benefit from his addition to our executive management team.”

At Microsoft, Lu will replace Brian McAndrews, the former boss of aQantive, a company acquired by Microsoft back in 2007.