WASHINGTON (Reuters) - The U.S. State Department has approved the potential sale to Bahrain of M270 Multiple Launch Rocket Systems Upgrade and related equipment for an estimated cost of $176 million, the Pentagon said on Thursday.

       The principal contractor will be the Lockheed Martin Corp, the Pentagon's Defense Security Cooperation Agency said in a news release.

       (Reporting by Eric Beech; Editing by Katharine Jackson)