Aug. 6 (Bloomberg) -- Russia's biggest oil companies missed a deadline for supplying regulators with information as part of an antitrust probe of wholesale fuel prices, the Federal Anti- Monopoly Service said.

The agency requested information from OAO Gazprom Neft, OAO Lukoil, TNK-BP, OAO Rosneft and OAO Surgutneftegaz and only Surgut complied on time, the watchdog said in a statement today. The regulator opened cases against the oil producers in July, saying they set ``monopolistically high prices'' on domestic diesel and jet fuel.

Russian Prime Minister Vladimir Putin is pushing his Cabinet to probe cases of price collusion. His criticism of steelmaker OAO Mechel last month for inflating domestic coking coal prices and possibly avoiding taxes helped shave almost $63 billion off the Russian stock market in one week.

The oil companies may have created ``discriminatory conditions for buyers in the wholesale markets,'' the agency said.

Putin said last month the anti-monopoly service should ``wake up'' and help ``destroy the fuel monopoly at airports.'' The regulator said on June 24 it may open criminal cases against oil companies after jet fuel prices surged 70 percent in Russia from November to June.

The anti-monopoly agency said it is considering unspecified penalties against the oil companies and their employees for not handing over details of their operations. The agency said it brought representatives of the police on trips to gather information from the companies earlier this week.

To contact the reporter on this story: Greg Walters in Moscow gwalters1@bloomberg.net

Last Updated: August 6, 2008 07:01 EDT