Microsoft is still looking for the right formula when it comes to search and advertising. Wednesday the company announced a batch of changes including a new Search and Ad Platform Group in the Platform Services Division. This follows news that Christopher Payne and Blake Irving are leaving the company.
—Satya Nadella will head the Search and Ad Platform Group, which now combines both under a single R&D head, as the announcement explains. Nadella’s current job is leader of Microsoft Dynamics; the transition should occur by April 19.  From the memo: “Aligning Search and our Ad Platform efforts under a single R&D leader is essential as we drive advances in our search, commerce, and payments infrastructure, and evaluate change-the-playing-field opportunities.”
—Tami Reller, corporate vice president of Microsoft Dynamics, will be the acting leader of that group reporting to Jeff Raikes, president, Microsoft Business Division.
—Harry Shum adds the responsibilities of chief scientist for the new group to his current role the leader of Microsoft Research Asia. He will coordinate short and long-term technology investments in “this key area across the company.”
Update: Mary Jo Foley explains the MSFT politics: the move takes Microsoft Live Search engineering and development away from the Windows Live family and SVP Steven Sinofsky. Instead it’s paired with Microsoft adCenter. She also has the rest of the direct report structure, including Rick Thompson, corporate VP in charge of the Windows Live Advertising and Monetization Platform—and the GMs of MSN Marketplaces, Microsoft search, search and mapping, search content acquisition.