Billionaire Mikhail Prokhorov's Onexim Group said Thursday that it would invest $10 billion over the next five years in a new company, Intergeo, to develop the mining assets he received from former partner Vladimir Potanin.

Intergeo would aim to become one of the world's top three copper, nickel and platinum producers, Prokhorov's Onexim Group said in a presentation posted online in its LiveJournal blog.

Over the next two years, Intergeo plans to invest an initial $250 million, Onexim spokesman Igor Petrov said.

"We will spend the money in the development of the fields, as well as building new production capacities," Petrov said. "It will be a unique experience of building a metals major from scratch."

Intergeo intends to produce 280,000 tons of copper and 150,000 tons of nickel annually, along with other metals, Onexim said in its presentation.

Intergeo's deposits hold 15 million tons of copper, 9 million tons of nickel and other metals including platinum and palladium, Onexim said. The new company will also seek out licenses for new reserves, Onexim said.

The new company's management team will include former Norilsk executives Maxim Finsky, Michael Page, Grigory Potapov and Alexander Stekhin, Onexim said.

"They are experienced enough in the field, plus our company will be a new challenge for them," Petrov said.

Analysts expressed skepticism that Intergeo's planned investment would be enough to get production up to speed. The new company would need to invest $15 billion to $20 billion over at least 10 years to reach intended production levels, said Oleg Petropavlovsky, an analyst at BrokerCreditInvest.

"These deposits are spread out widely across the country and date from the Soviet times, so potential production figures can only be preliminary," he said.

Intergeo will also face a shortage of qualified employees, both for management positions and for construction needs, he said.

Because of ongoing disagreements between Prokhorov and Potanin, Norilsk is not likely to have any relations with Intergeo, Petropavlovsky said.

Intergeo will sell its products both domestically and abroad, Petrov said. The new company would be open to cooperation with foreign metal giants such as BHP Billiton and RioTinto, Petrov said.

In a separate development, Onexim chief executive Denis Razumov told reporters Thursday that the group would withdraw its bid for the huge Udokan copper field in eastern Siberia, which has attracted bids from influential business groups, including Norilsk and billionaire Oleg Deripaska's mining company Strikeforce.

Petrov explained Onexim's decision to withdraw from the bidding as aimed at avoiding "a conflict of interest, as Mikhail Prokhorov is the president of Onexim Group, and also a board member of Norilsk Nickel." He said Intergeo was ready to cooperate with the winner of the tender, to be announced Sept. 14.