Ukrainian national Yury Soloshenko, 73, was convicted Wednesday by a Moscow city court of espionage and sentenced to six years in prison, the Interfax news agency reported.
Soloshenko, who retired as director of a Ukrainian factory in 2010, was convicted of attempting to buy secret components for S-300 surface-to-air missile systems, the TASS news agency reported, citing the Russian Federal Security Service (FSB).
The court also ordered the confiscation of $6,000, the sum he was allegedly planning to use to purchase the missile components.
Soloshenko pleaded guilty and declined to appeal the court ruling, his lawyer Gennady Blokhin told the RBC news agency.
The prosecutors had originally asked for a 10-year prison sentence, RBC reported.
According to the FSB, Soloshenko was arrested in August last year and had been acting on behalf of two state-controlled Ukrainian production factories, TASS reported.
The FSB also said that Soloshenko's case was not the first attempt by a Ukrainian national to buy and smuggle secret military technology across the border. In December 2014 Ukrainian national Denis Danchenko was deported from Russia after attempting to buy surface-to-air Buk missile system components, TASS reported.
According to Soloshenko's son Alexander, his father spent 50 years working in Soviet and Ukrainian defense production facilities, including 20 years as director for Ukraine's Znamya factory, which produced electric components for air defense systems before going bankrupt in 2012, Interfax reported.
Alexander Soloshenko said his father was repeatedly asked to mediate in discussions between Ukrainian and Russian defense manufacturers, and the factory, in his words, worked mainly with Russian orders.
"There was nothing secret, neither on our side nor on the Russian side. It was one system," Alexander Soloshenko told Interfax, calling the espionage charges "absurd."
Blokhin, Soloshenko's lawyer, said Soloshenko could be extradited to Ukraine, RBC reported.