The merged entity has interests in gold, nickel and platinum

African Rainbow Minerals, Anglovaal and Harmony have agreed to pool resources, putting Patrice Motsepe, a leading black entrepreneur, in charge.

The deal marks a step towards meeting ambitious government targets for the transfer of mining assets to groups disadvantaged by apartheid rule.

Harmony is already the world's fifth largest gold producer.

Under the new deal, Mr Motsepe's ARMgold takes control of Anglovaal, while Harmony will pay 2.89bn rand (�0.25bn) for a 42.2% stake in Anglovaal's gold division.

When an empowerment charter for the mining sector was leaked, it caused alarm among investors and shares prices tumbled South Africa's struggle to spread the wealth

ARMgold recently merged with Harmony, meaning the three companies are to be inter-locked in a complex series of asset swaps and share issues.

The merged ARM and Harmony empire has interests in platinum, nickel and ferrous metals in addition to its significant gold resources.

Black empowerment

The complexity of the deal is driven in part by the demands of the South Africa's Black Economic Empowerment (BEE) charter, which calls for 15% of mining companies' local assets to have non-white ownership within 5 years and 26% in 10 years.

The government is under pressure to redress the economic imbalance left by decades of apartheid rule, which excluded the country's huge black majority from the economy.

Mr Motsepe, also chairman of the National Federated Chamber of Commerce, is one of a small number of high-profile black executives to have penetrated the upper echelons of big business.

Black-controlled companies account for just 3% of companies listed on the Johannesburg Securities Exchange, and about 75% of top managers are white.

Room at the top

The BEE initiatives are controversial.

The policy is variously denounced for being discriminatory and for failing to take account of economic realities, artificially filling posts with underqualified candidates.

The policy is also accused of nurturing a small coterie of politically well-connected businessmen without addressing the widescale wealth gap in the country.