Rosneft has decided against bidding for gas assets being sold by diamond miner Alrosa, at least for now, the Russian energy company said Jan. 10, adding the auction terms were unacceptable.

The world’s largest producer of rough diamonds plans to sell its gas assets in Russia’s Yamalo-Nenets region during an auction Feb. 19 and has set a starting price of 30 billion roubles ($519 million).

Rosneft and its subsidiary Bashneft had applied to the Federal Anti-Monopoly Service (FAS) for clearance to take part in the auction.

“We have applied for the permission to take part in the auction. The request itself is not participation,” Rosneft spokesman Mikhail Leontyev said.

Rosneft had misgivings about the resources of the deposits, Leontyev said.

The company also did not agree with the sales terms, according to which the future buyer would not be able to log claims with the seller in the event the resources turn out to be lower than initially stated.

“At the moment, with the information we have about the asset, we can’t risk the interest of our shareholders. We won’t play under such rules,” the spokesman said, adding that Rosneft had filed complaints to the FAS, Finance Ministry and subsoil agency Rosnedra.

Earlier on Jan. 10, the head of FAS, Igor Artemyev, said the regulator would analyze the sales terms, Interfax news agency reported.

Russia’s top non-state gas producer Novatek has said it is interested in buying Alrosa’s gas fields. The Finance Ministry has said that seven bidders were expected to take part in the auction.