South African miner Gold Fields, which warded off a hostile takeover bid by Harmony, has delivered a fresh blow to its rival by moving to gain full control of a mine with reserves of 29.3 million ounces.

The South Deep Mine, about 45 kilometres (28 miles) southwest of Johannesburg, is a coveted acquisition given that many gold pits in the country are reaching the end of their mining life.

"It's a known resource and it is very large," said Mandla Mapondera, gold analyst at Old Mutual Asset Managers.

"There have not been many new gold discoveries in the world in recent years, at least not in terms of sizeable orebodies," he said.

Gold Fields, the world's fourth biggest miner, Monday announced that it had acquired a 50-percent stake in South Deep from Canada's Barrick Gold and also entered into a call and put option to buy the remainder from the Western Areas group, which owns the other 50 percent of South Deep.

"It is a positive move on the basis that it gives Gold Fields access to large reserves and to another mine with very long life," Mapondera said, adding that the company was "very successfully mining right next door" at Kloof.

All this means a fresh loss of face for Gold Fields' rival Harmony, which had managed to acquire a 29-percent stake in Western Areas some months ago.

In May 2005, Harmony failed with a hostile takeover bid for Gold Fields after a seven-month battle characterised by court battles and mud-slinging.

Old Mutual's Mapondera said the key question was whether Harmony had "the capacity to swallow South Deep as a whole? The answer is probably no."

For Harmony boss Bernard Swanepoel, who built up his company group by acquiring ageing gold mines and drastically slashing production costs, it was a bitter pill to swallow.

When asked how he would respond to Gold Fields' option to buy the remainder of Western Areas, he remained cagey, merely indicating that a lot of things could have changed in the few months the offer will take to be finalised.

Gold Fields, which also has mining interests in Ghana, Australia, Venezuela and Peru with an annual production of 4.2 million ounces, plans to develop and deepen its investments and operations.

Four days before the South Deep announcement, Gold Fields said it was investing 4.7 billion rands (500 million euros) in South Africa to deepen exploration at its mines in Kloof and Driefontein near South Deep.

"South Africa remains one of the premier gold mining destinations in the world," Gold Fields chief executive officer Ian Cockerill said.

"These investments will extend our South African profile to at least 2035, strengthening further the solid foundation from which Gold Fields will continue to pursue its existing commitment to international growth."

Since gold was discovered near Johannesburg in 1886, South African mines have accounted for the major share of total global output.

Although the country remains the world's top gold producer, output is dwindling. In 2005, output totalled 297.3 tons, a 13.9-percent decline from a year ago.