Raytheon [RTN] said it was awarded a $685.7 million Foreign Military Sales contract for additional new fire units for Taiwan’s Patriot Air and Missile Defense System.

“Our partnership with Taiwan dates back more than 45 years, and we are committed to providing Taiwan with the best air and missile defense system capability available,” said Sanjay Kapoor, vice president for Integrated Air and Missile Defense at Raytheon’s Integrated Defense Systems business (IDS).

The contract, issued by the Army Aviation and Missile Command, Redstone Arsenal, Ala., is for new Patriot fire units with new advanced technology, improved man-machine interface and reduced life-cycle costs.

This award comes in addition to the one received in 2009 for new systems for Taiwan and the 2008 contracts to upgrade Taiwan’s existing systems. Raytheon recently delivered the first Configuration-3 radar system to Taiwan, completing the upgrade 10 months ahead of the original program plan requested by Taiwan, the company said recently.

The Patriot air and missile defense system protects against a full range of advanced threats, including aircraft, tactical ballistic missiles, cruise missiles and unmanned aerial vehicles. Twelve nations have bought the Patriot system.

Raytheon is the prime contractor for both domestic and international Patriot Air and Missile Defense Systems and system integrator for Patriot Advanced Capability-3 missiles.