LUKoil, Gazprom Neft, TNK-BP Holding, Rosneft and Surgutneftegaz are suspected of price fixing, in violation of the law on the protection of competitiveness.
The service accused the companies of abusing their dominant market positions through "establishing a monopolistically high price on wholesale markets of aviation kerosene and diesel fuel in the Russian Federation."
The service said Monday it would soon launch a number of investigations and adopt antimonopoly measures regarding the aviation fuel market.
Last week, Russian Prime Minister Vladimir Putin said that should the antimonopoly service fail to adopt measures over increasing prices for aviation fuel, heads would roll. He added that aviation fuel prices in Russia were the highest in the world, which was unacceptable.
State-owned Rosneft and Russian-British joint venture TNK-BP told RIA Novosti that they adhered to Russian law and would cooperate with the antimonopoly service's investigation.
Gazprom Neft, the oil producing arm of Russian energy giant Gazprom, said the company worked in market conditions and that all fuel price changes were pegged to changing oil prices on the world and domestic markets.
"Besides, the list of companies accused includes all large Russian oil companies, which says that collusion or violation of competitiveness conditions would be impossible," a spokeswoman said.
A LUKoil representative refused to comment until the investigation was completed, and Surgutneftegaz was unavailable for comment.
