Accra - Any company that buys Ghana's Ashanti Goldfields must be willing to spend as much as $1 billion to access the deep underground reserves of its Obuasi mine, chief executive Sam Jonah said yesterday.

"The key is Obuasi," Jonah said. "We are looking to a partner who wants to share that risk and the reward." Ashanti's board and its largest shareholder, Lonmin, the world's third-biggest platinum producer, have accepted a $1.31 billion stock offer by AngloGold, the world's second-largest gold mining company.

Randgold Resources, based in Jersey, Channel Islands, has said it may offer $1.5 billion of its own stock for Ashanti.

Investors may favour the AngloGold bid, which has a market value of R67 billion, because it can raise money more easily than Randgold, which has a market capitalisation of $663 million. AngloGold has said it would spend $680 million on Obuasi.

Randgold chief executive Mark Bristow last month declined to say how Randgold would fund the project.

"Once you bring in very large capital commitments it blows Randgold's bid out of the water," said Leon Esterhuizen, an analyst at Investec Securities in Johannesburg.

AngloGold shares closed R9.50 up at R317.21 in Johannesburg. Randgold stock rose 37.5p to close at ?15.425 in London. Ashanti's shares were up 0.04c at e9.56 (R79.58) in Germany.

Buying Ashanti, the first African company to be listed on the New York Stock Exchange, would help AngloGold chief executive Bobby Godsell boost reserves by 31 percent and cut costs by $15 million a year.

The purchase would lift AngloGold's output by 27 percent to within 1.3 percent of Newmont Mining, the world's biggest gold mining company.

"Obuasi is fully explored; it should be the largest mine within the group, whether we join AngloGold or Randgold," said Jonah, who will be president of the merged company if the AngloGold purchase goes through.

"It has huge reserves."- Bloomberg