The Defense Security Cooperation Agency notified Congress this month of the possible Foreign Military Sale, the DSCA said on its Web site.
Prime contractors for the sale would be Raytheon Missile Systems in Tucson and BAE Systems in Aberdeen, S.D.
The capability package includes three MK25 Quad Pack canisters, four MK783 shipping containers, support and test equipment, publications and technical documentation, personnel training and training equipment.
The agency said the proposed sale "will contribute to the foreign policy and national security of the United States by increasing the ability of Thailand to contribute to regional security and improving interoperability with the U.S. military in operational and exercise scenarios."
The sale is consistent with U.S. national interests" because the ESSM would provide ship self-defense capability for Thailand, which will contribute to the military balance in the area, the DSCA said.
The tail-controlled SeaSparrow missile is used by the U.S. Navy and 11 international fleets to defend against highly maneuverable anti-ship cruise missiles, as well as surface and low-velocity air threats.
No offset agreements are proposed in connection with the potential sale, nor will there be additional U.S. government or contractor representatives stationed in Thailand, the DSCA said.
Earlier this month Raytheon said it had delivered the 2,000th Evolved SeaSparrow Missile to the NATO SeaSparrow Consortium, a group of countries that share information on the deployment and maintenance of the ship-defense system.
The consortium includes the United States, Greece, Australia, Belgium, Canada, Germany, Denmark, Netherlands, Norway, Portugal, Spain and Turkey.
"We have delivered ESSMs for a decade and expect continued production past 2017," Ed Roesly, Raytheon Missile Systems' ESSM program director, said.
The Australian frigate Perth recently fired two ESSMs during an advanced air warfare weapons event at Exercise Rim of the Pacific -- RIMPAC 2012, around Hawaii.
The Anzac class Perth joined sister ship Darwin in a six-ship formation with Canadian and U.S. ships to conduct a coordinated defense of the group against multiple-target drones that flew realistic profiles against the ships.
Perth fired its two ESSMs at two targets and used the Australian-designed Nulka anti-missile systems to decoy another. Nulka is a rocket-propelled, disposable, offboard, active decoy designed to draw away anti-ship missiles from their targets.
The Nulka was developed and originally manufactured by AWA Defense Industries, now BAE Systems Australia.