A court in Russia has convicted a retired colonel of spying for the United States and sentenced him to 12 years in prison.

Security service officials say that Vladimir Lazar, a former senior officer with the military-technical department of the Russian Armed Forces General Staff, was convicted in a Moscow city court for selling sensitive maps to the U.S. Defense Department.

The court has ruled that Lazar will be sent to a high-security prison and stripped of his military rank.

Prosecutors said Lazar purchased several computer disks with more than 7,000 images of classified maps of Russia from a collector in 2008 and smuggled them to neighboring Belarus, where they were allegedly passed to an American intelligence agent.

Officials say the maps could be used for planning military operations against Russia.

Lazar had served with the General Staff of the Russian armed forces in Moscow before his retirement about 10 years ago.

Earlier this month, a regional court in the city of Yekaterinburg convicted defense plant worker Alexander Gniteyev of passing information about Russia's missile secrets to a foreign intelligence agency and sentenced him to eight years in prison.

And in February, a military court sentenced testing engineer Vladimir Nesterets of providing the United States with secret information on new missiles. He was sentenced to 13 years.

Russia is fiercely opposed to U.S.-led NATO missile defense plans for Europe, which Moscow sees as a potential threat to its nuclear forces.