Lockheed Martin Corp., the largest U.S. defense contractor, announced plans Monday to acquire Sikorsky Aircraft, maker of the military UH-60 Black Hawk helicopter and its many variants, for $9 billion.

The acquisition, expected to close near the first of the year, formalizes a longtime partnership between the two companies that produced U.S. Navy versions of the MH-60 helicopter for anti-submarine warfare (ASW) and other kinds of naval warfare, as well as the VH-92 Presidential Helicopter and Combat Rescue Helicopter.

Although the Lockheed Martin Mission Systems and Training segment in Owego, N.Y., is listed as prime contractor for the MH-60 Seahawk, Sikorsky provides the actual aircraft, which is based on its venerable UH-60 helicopter.

via Lockheed Martin to acquire UH-60 Black Hawk helicopter designer Sikorsky for $9 billion.