The Defense Ministry opposes a contract signed between Moscow's Yakovlev aircraft design bureau and the American aerospace giant Lockheed-Martin to help develop a new U.S. supersonic fighter capable of vertical takeoff and landing, or VTOL, a ministry official said.


The official, who declined to be named, said the contract "could be a threat to national security and should be thoroughly examined."


"The control departments of the ministry did not give any permission to the transfer of the technology," he said in an interview Thursday. The company has just preliminary permission to start contacts."


The contract, signed earlier this year, is the latest partnership between Russia's struggling aviation companies and their Western counterparts, all trying to make ends meet in the post-Cold War world.


Yakovlev's new Yak-141 fighter aircraft, which the Russian navy and air force does not have the money to put into full-scale production, represents the second generation of Russian VTOL technology. It is the only VTOL fighter in the world capable of supersonic flight.


Lockheed officials could not be reached for comment.