* Bing engineering chief to head unit
* Muglia departure announced last month
NEW YORK, Feb 9 (Reuters) - Microsoft Corp (MSFT.O) named Satya Nadella on Wednesday as the head of its $15 billion server and tools business, replacing Bob Muglia, who announced plans to step aside last month.
Nadella, 43, is a 19-year Microsoft veteran, who most recently led engineering for Microsoft’s online services business, which includes the search engine Bing and Internet portal MSN. (Reporting by Bill Rigby, editing by Gerald E. McCormick)