Russia extends Udokan copper field bid deadline

MOSCOW, May 13 (Reuters) - Russia's Natural Resources Ministry on Tuesday extended until June 11 a deadline for accepting bids for the rights to a huge Siberian copper field, saying potential bidders needed more time to prepare documents.

Rosnedra, the federal subsoil agency within the ministry, said in a separate statement the contest for the Udokan deposit would now take place on Aug. 14, nearly a month later than the July 17 contest that had originally been planned.

Neither the ministry nor its subdivision said whether any bids had already been made for the field, one of only two untapped metals deposits large enough to be declared "strategic" by the government. The other is the Sukhoi Log gold field.

Udokan, in the Chita region of eastern Siberia, will require investment of around $1.6 billion, the ministry said. It will be able to produce 187,000 tonnes of copper annually, equivalent to 15 percent of Russia's total copper production today.

Russian billionaire Oleg Deripaska, state railway monopoly Russian Railways and mining giant Norilsk Nickel (GMKN.MM: Quote, Profile, Research) have all expressed their interest in bidding for Udokan, estimated to contain 13.4 million tonnes of extractable copper metal.

Russian media reported last month state conglomerate Russian Technologies, whose wide-ranging asset portfolio includes titanium producer VSMPO Avisma (VSMO.MM: Quote, Profile, Research), was also planning to bid.

(Reporting by Polina Devitt, writing by Aleksandras Budrys; editing by Chris Johnson)