Vladimir Kvachkov was sentenced to 13 years in prison, RIA Novosti reported. He was tried in the Moscow City Court.
Kvachkov received the Order of the Red Star and the Order of Courage after he was wounded in Afghanistan in 1984 while commanding a special forces unit. He also served with the military intelligence service.
Prosecutors said that Kvachkov, a leader of the People's Liberation Front of Russia, was involved in a plan to seize weapons and march on Moscow. He denied the charges.
Kvachkov had been tried and acquitted of an alleged attempt in 2005 to kill former Unified Energy Systems head Anatoly Chubais. Chubais, heavily involved in restructuring the Russian economy after the collapse of the Soviet Union, is hated by many in the Russian opposition.