South Africa's AngloGold has extended its offer for Australia's Normandy Mining for another week.

It hopes that this will buy it enough time to see off Newmont, its rival US bidder for the Australian company.

The choice for Normandy shareholders has been between big promises from AngloGold - and a higher cash offer from Newmont.

However, AngloGold's rising share price has seen the gap between the two offers narrow.

AngloGold's offer is now worth A$1.93 a share versus Denver-based Newmont's A$1.95 a share bid.

Whoever wins control of Normandy - one of Australia's biggest gold producers - will secure the place as the world's biggest gold producer.

On Friday, AngloGold had secured support of about 6.5% of shares in Normandy but it still needs 3.5% more support to be able to block the rival bid under Australian law.

AngloGold may only have secured a small percentage of support, but some argue that this support is growing, aided by AngloGold's rising share price.

In an interview with Reuters, AngloGold finance director Jonathan Best said: "Our goal is 50.1% and if we don't get that we would have to decide what our options are. Clearly we want as much as possible."

Rising share price

The battle for Normandy began last September when AngloGold launched a surprise bid.

In November, Newmont came back with a rival offer, and over the past few weeks both companies have improved their bids as they seek to land the knock-out blow.

"The continuing strength of AngloGold's share price, which has risen by 16% since we announced our offer for Normandy on 5 September, gives me great confidence in the upside potential to be had from accepting the AngloGold offer," Bobby Godsell, AngloGold chief executive officer and chairman said in a statement.

The AngloGold stock has been helped in part by the weakness of South Africa's currency, the rand, which has encouraged people to put their money into gold stocks.