MOSCOW, November 3 (RIA Novosti) - The Russian anti-monopoly authorities said they have inquired leading Russian oil refineries about reasons that recently led to reduced production of oil derivatives and higher prices.

Some media reports said this week that gasoline prices could rise 10-15% in Moscow and the Moscow Region due to technical maintenance works at three refineries in central Russia, including one in Moscow.

"Inquiries have been sent to find out the reasons behind the discrepancy between the planned and the actual reduction in output," said Alexander Pirozhenko, head of the energy control department in the Federal Anti-Monopoly Service.

He said the deficit in oil products had caused serious price growth in central Russia in the past few weeks.

"The inquiry will help conclude on how market players complied with the anti-monopoly legislation," Pirozhenko said.

An official in the Moscow Fuel Association uniting two thirds of Moscow gasoline stations spoke about economic prerequisites for gasoline price growth in the city.

TNK-BP and LUKoil controlling two oil refineries in question in central Russia have meanwhile denied reports about expected cuts in their output.

Yury Roslyak, first deputy mayor of Moscow, also dismissed rumors about any connection between potential price growth and the production of the Moscow oil refinery.