The Missile Defense Agency awarded Lockheed Martin [LMT] a sole-source letter contract worth approximately $2 billion to provide at least 42 Terminal High-Altitude Area Defense (THAAD) interceptors, the Defense Department said recently.

These interceptors are added to the current Undefinitized Contract Action (UCA) under the existing THAAD production contract (HQ0147-07-C-0196).

DoD intends to combine this procurement with the Foreign Military Sale of 96 THAAD interceptors to the United Arab Emirates to gain synergy cost savings, MDA said. This UCA covers the combined procurement of a minimum of 138 interceptors.

The work will be performed at Lockheed Martin Space Systems in Sunnyvale, Calif., with final assembly in Troy, Ala. The performance period extends from June 4, 2012 to July 31, 2018.

Definitization of the UCA is expected no later than Nov. 30.

Lockheed Martin did not respond to a request for comment.

In October, THAAD successfully detected, tracked and destroyed two targets simultaneously in an initial operational test and evaluation test: A short range and a medium range ballistic missile.