The Missile Defense Agency is announcing the award of a sole-source letter contract to Lockheed Martin Space Systems Co. (LMSSC), Sunnyvale, Calif., as an undefinitized contract action (UCA) at a total not-to-exceed price of $2,023,590,000. This award is made under the existing Terminal High Altitude Area Defense (THAAD) production contract HQ0147-07-C-0196. Under this contract, LMSSC will supply a minimum of 42 THAAD interceptors, Lots 3 and 4. The government intends to combine this procurement with the Foreign Military Sales for the United Arab Emirates procurement of 96 interceptors, previously synopsized as an UCA under basic ordering agreement HQ0147-12-G-9000, in order to gain synergy cost savings. This UCA covers the combined procurement of a minimum of 138 interceptors. This work will be managed in Sunnyvale, Calif., with final assembly performed in Troy, Ala. The performance period extends from June 4, 2012 through July 31, 2018. This action was synopsized as a sole-source requirement to LMSSC in Federal Business Opportunities; one response was received. Definitization of the UCA is anticipated no later than Nov. 30, 2012. The Missile Defense Agency, THAAD Program Office, Redstone Arsenal, Ala., is the contracting activity.