ACCRA, Aug 18 (Reuters) - In the billion-dollar bidding war for Ashanti Goldfields ASL.N , the bidders' plans for its prized Obuasi mine may matter more than price, sources close to the firm and its controlling shareholder, Ghana's government, said on Monday.

Mining giant AngloGold ANGJ.J has promised to pour huge investment into Obuasi as part of its all-share bid, which lags in value an all-stock offer from smaller rival Randgold Resources RRS.L , though the difference between the bids is shrinking fast.

"What is important to Ghana is what happens to Obuasi Deeps. That's one of the lifelines of the company," a source close to the government said. Ghana's government holds 17 percent of the gold miner and a crucial veto.

"The highest price may not necessarily be the best offer. It's not about price, it's about the totality of the whole package," a source close to Ashanti told Reuters.

London-based Randgold Resources launched a bidding battle for Ashanti on August 8 only days after the Ghanaian firm had formally accepted a deal from the world's second-biggest gold miner, AngloGold.

A spokesman for AngloGold said on Monday there was currently no reason for it to increase its offer, confirming comments on Friday by the company's chief executive Bobby Godsell.

"The rational analysis is that AngloGold has all of the ticks in the right boxes. Barring something quite drastic, I don't see them not getting it," said Patrice Rassou, fund manager at Old Mutual Asset Managers in Johannesburg.

AngloGold, South Africa's biggest bullion producer, is seen by investors and analysts as having greater financial muscle and operational expertise than Randgold, which has only half the market capitalisation of Ashanti.

AngloGold has pledged to invest around $700 million in Obuasi, a massive mine currently supporting 9,000 jobs, including a plan to extend the life of the mine by digging thousands of metres deeper.

"You don't want to just give a cash windfall to shareholders and endanger the future of Obuasi Deeps," Rassou said.

Ghana should make a decision quickly, the source close to the government added, because otherwise companies with more serious offers might lose interest. "People don't want to deal with a party that dithers," the source said.

NORTH AMERICANS INTERESTED?

Ghana's government said on Friday it was open to other offers, and Britain's Independent newspaper said at the weekend that two Canadian firms -- Placer Dome PDG.TO and Barrick HCX.TO -- could be interested, but the source close to Ashanti said no formal offers had been received from the firms.

A spokeswoman for Placer Dome said the company could not comment on rumours, although she added that the firm had a team of people who were constantly evaluating acquisitions.

"Acquisitions will continue to be part of our growth strategy where the right deals arise," the spokeswoman said.

Barrick declined comment on the report, but said its African strategy was focused in the east of the continent in Tanzania.

Analysts said the bid by Randgold would have more credibility if it partnered with bigger firms like Barrick, the third-largest gold producer based on 2002 data, or Placer, ranked world number seven.

But the North Americans don't have as much experience in deep level mining as South African firms, Rassou said.

In New York, Ashanti shares were little changed at $9.67, Randgold had shed 2.19 percent by 1634 GMT, while AngloGold closed down 3.1 percent in Johannesburg after gold prices slid.

When Randgold first announced its all-share offer 10 days ago it had a 30 percent premium to AngloGold's own stock offer, but changes in their respective values has quickly eroded that premium. AngloGold's bid now values Ashanti at around $1.25 billion, while Randgold's bid is worth $1.35 billion, a difference of just 7.5 percent.