WASHINGTON, Jan. 17 (Xinhua) -- The U.S. State Department on Wednesday approved a possible huge military sale to Saudi Arabia of continuation of missile system support services for an estimated cost of 500 million U.S. dollars.

According to an announcement published by the Defense Security Cooperation Agency under the U.S. Defense Ministry, the agency has notified the Congress of this sale later on Wednesday.

According to the document, Saudi Arabia has requested to purchase continued participation, technical assistance, and support in the Patriot Legacy Field Surveillance Program (FSP), the Patriot Advanced Capability 3 (PAC-3) FSP and the Patriot Engineering Services Program (ESP).

The purchase list also included Patriot and HAWK Missile System spare parts and repair and return management services and component repairs, and other related elements of logistics and program support.

The principal contractors are Lockheed Martin, Bethesda, MD for the FSP and Raytheon Company, Andover, and MA for the ESP. Support teams of four to 10 people will travel to Saudi Arabia on a temporary basis for one to three weeks at a time.

The Defense Security Cooperation Agency said this proposed sale, a continuation of current support, would help improve Riyadh's security.