Sikorsky, a subsidiary of United Technologies Corp. [UTX], said yesterday it signed a five-year, $8.5 billion contract to provide the Army and Navy with a baseline quantity of 653 H-60 Black Hawk and Seahawk helicopters through December 2017.

The five-year agreement also allows the Army and Navy to order as many as 263 more aircraft within the same contractual terms, Sikorsky said in a statement. If exercised, the operational purchases could push the contract value as high as $11.7 billion. Actual production quantities will be determined year-by-year over the life of the program based on funding allocations set by Congress and Pentagon acquisition priorities.

The base contract includes UH-60M utility and HH-60M Medevac helicopters for the Army and MH-60R and MH-60S helicopters for the Navy. To reach the full baseline value of $8.5 billion, the services are ordering aircraft in the base agreement to be sold via the Foreign Military Sales program, Sikorsky said in a statement.

Black Hawk and Seahawk aircraft deliveries under the new contract will begin this month. Sikorsky produces the two H-60M Black Hawk and two MH-60 Seahawk aircraft models on four separate production lines at its final assembly facility in Stratford, Conn., and West Palm Beach, Fla.