Energy giant Rosneft, which acquired the Yukos assets after its founder, Mikhail Khodorkovsky, was jailed, said that all its dealings were lawful.
Mr Lavrov responded to an initial report of the verdict on Monday at a briefing, saying: "It goes without saying that Russia — the agencies that represent Russia in this case — will use all the legal options it has to uphold its position."
Rosneft said in a statement that it "considers that all its deals in acquiring Yukos’s former assets and also all its other actions towards Yukos were fully lawful and were carried out according to the legislation in force". Yukos was sold off in opaque auctions to state companies led by Rosneft.
The government firm was then a small player but today stands as the world’s biggest publicly traded producer of oil.