"The appeal by the defendant asks for the guilty verdict to be annulled and the criminal case closed", Georgy Kaganer said.
Alexei Pichugin was given a life sentence on August 6 for the murders of an entrepreneur and a Siberian oil town mayor, and the attempted murder of a businessman.
The ruling came after the Supreme Court revoked an earlier 24-year sentence, and ordered a re-trial, following appeals from both prosecutors and the defense team.
Pichugin denies the charges against him, and his lawyers earlier alleged that their client was put in prison "for one purpose only - to put pressure on Yukos executives."
The criminal case is one of several to involve officials of bankrupt oil company Yukos. Mikhail Khodorkovsky, founder of what was once Russia's largest oil producer, and his business partner, Platon Lebedev are serving eight-year prison terms on fraud and tax evasion charges.
Yukos assets have now been fully sold through liquidation auctions. The key oil-producing assets have been bought up by state-controlled Rosneft, making it the country's largest crude producer.