File photo of the US Navy guided-missile destroyer USS Lassen underway in the Pacific Ocean Thomson Reuters WASHINGTON (Reuters) - Northrop Grumman Corp has won a contract worth $93.08 million to build a full-scale demonstrator of a new unmanned spy plane - a flying wing with large counter-rotating propellers - that would take off and land on destroyers and frigates, the Pentagon said on Thursday.

Northrop has been working on a design for the new drone for several years under a joint program called Tern that is led by the Defense Advanced Research Projects Agency and the U.S. Navy's Office of Naval Research.

Navy officials would like unmanned aerial systems to carry out intelligence, surveillance and reconnaissance measures from smaller warships, but current drones are unable to take off and land from confined spaces at sea and then stay airborne for long periods.

The contract calls for Northrop to build a full-scale medium-altitude demonstration aircraft that would operate on small warships. If ground-based testing succeeds, the contract would fund an at-sea demonstration, according to a defense official who was not authorized to speak publicly.

The only other competitor for the contract, Aerovironment Inc did not submit a bid, the official said.

Northrop officials discussed the Tern design concept with reporters earlier this month and showed a model of a 40-foot flying wing that lands and takes off sitting on its tail, and then tilts to fly with the rotors in the front.

The Navy designed an experimental ship-based fighter called the Convair XFY-1 Pogo in the 1950s to provide air support for ships, but it never moved past the prototype stage.

(Reporting by Andrea Shalal and Eric Walsh; Editing by Leslie Adler)