AEROSPACE

Lockheed Martin Becomes Top Defense Contractor: The defense giant created in a merger last year of Lockheed Corp. and Martin Marietta Corp., has replaced McDonnell Douglas Corp. as the nation’s largest defense contractor, according to the Pentagon. Lockheed Martin Corp. had $10.5 billion in contract awards in fiscal 1995, compared with $8 billion for McDonnell Douglas, which slipped to No. 2. Before the merger, Lockheed ranked No. 2 and Martin Marietta was No. 4, according to 1994 fiscal figures. Northrop Grumman Corp., which ranked third in 1994, fell to No. 5. It was replaced in the third spot by Tenneco Inc., which had been ranked 31st the year before.