Boeing Co (BA.N) said Tuesday that President Dennis Muilenburg will take over as chief executive officer July 1, a transition that comes as the aerospace giant tries to keep pace with an historic boom in the commercial jet market and build its defense business amid tight military budgets. Muilenburg, 51, will succeed 65-year-old Jim McNerney, who picked Muilenburg as heir apparent in 2013. Muilenburg, in an interview, signaled no new direction, and did not discuss defense as a challenge.