Russia anti-monopoly service says may request lower fines on LUKoil, Gazprom Neft

"We will agree to seal a deal with [LUKoil and Gazpromneft] only on conditions analogous with those agreed to by TNK-BP," Artemyev said.

An arbitration court in western Siberia lowered anti-monopoly fines on TNK-BP from 4.2 billion rubles ($136 million) to 1.17 billion ($37.9 million) last week after the company confessed to hiking prices on fuel.

Artemyev said a fine against Rosneft may also be reduced from 5.28 billion rubles ($171 million) to 2 billion ($64.8 million).