Global mining giant Anglo American plc agreed to take control of legendary South African diamond company De Beers by paying $5.1 billion for the Oppenheimer family’s 40 percent interest.

At the closing of the deal, Anglo-American will have an 85 percent in stake in De Beers, the largest diamond distributor in the world.

The remaining 15 percent will be held by the government of Botswana in southern Africa.

Nicky Oppenheimer, chairman of De Beers and grandson of company luminary Ernest Oppenheimer, said of the deal: This has been a momentous and difficult decision as my family has been in the diamond industry for more than 100 years and part of De Beers for over 80 years. After careful and deliberate consideration of the offer, and what is in the best interests of the family, we unanimously agreed to accept Anglo American's offer. I am certain that Anglo American will provide strong support to [chief executive] Philippe Mellier and the De Beers management team.”

Cynthia Carroll, chief executive of Anglo American, said in a statement: This transaction is a unique opportunity for Anglo American to consolidate control of the world's leading diamond company, De Beers. [This] announcement marks our commitment to an industry with highly attractive long-term supply and demand fundamentals.

Botswana’s minister of minerals, energy, and water resources, Ponatshego H Kedikilwe, stated: “We are grateful to the Oppenheimer family for their vision and contribution to the diamond industry and to Botswana and we will proudly take forward that legacy with Anglo American.”

Sir John Parker, chairman of Anglo American, added: “The purchase of an incremental interest in De Beers is fully aligned with the Board’s strategic priorities. We look forward to increasing our involvement in the business and building strong links and relationships with De Beers.”

The diamond mining industry is currently dominated by two global players, De Beers and Zao Alrosa of Russia.

De Beers is one of the most famous and iconic companies on earth – virtually synonymous with diamonds and South Africa.

The company was originally founded in 1888 by notorious empire-builder Cecil Rhodes. In 1927, Ernest Oppenheimer (the original founder of Anglo American) took control of De Beers,

The proposed transaction remains subject to, among other conditions, Anglo American stockholder approval and also to regulatory and government approvals.

The deal is expected to close in the second half of 2012.