June 28 (Reuters) - The U.S. Army awarded Lockheed Martin a multi-year contract worth $4.5 billion for its air defense Patriot Missiles system, the Pentagon said on Friday.

The contract covers 870 PAC-3 MSE missiles and associated hardware.

Lockheed is manufacturing the newest version of the interceptors that arm the Patriot, known as PAC-3 MSE, which cost about $4 million each, according to Army budget documents.