Northrop Grumman Chairman and CEO Ronald Sugar is retiring at the end of the year.
The company says Sugar will be replaced by Northrop President and Chief Operating Officer Wes Bush, effective Jan. 1.
Sugar was elected chairman and CEO in 2003. He joined the company following its 2001 acquisition of Litton Industries.
Bush was named president in May 2006 and COO in March 2007.
Los Angeles-based Northrop is the second largest U.S. defense contractor by revenue, trailing only Lockheed Martin. It had total sales of $34 billion in 2008.