The move, which is a blow to South Africa's fragile economy, will create a major international mining powerhouse with a stock market valuation of about pounds 6bn, ensuring that it becomes a member of the FTSE 100 index of leading companies.
The new company will reunite Anglo American's South African operations with its assets around the rest of the world, creating a sprawling group with interests in diamonds, gold, platinum, coal, minerals and a brace of other industrial operations.
In a complex series of transactions, Anglo American will merge with Minorco, the Luxembourg-based company that controls most of its operations outside South Africa.
At the same time, it will take full control of Amcoal, its 57 per cent- owned coal subsidiary, and Amic, an industrial group with interests ranging from brewing to chemicals.
De Beers, the diamond group with which Anglo American has a close association, will own about 40 per cent of the new company, while the Oppenheimer family, descended from Ernest Oppenheimer, Anglo American's founder, will hold a 9 per cent stake.
The move is the result of a strategic review started last year by Julian Ogilvie Thompson, Anglo American's chairman.
"I think what we are marking today is the end of the financial structures that were imposed on us by apartheid," Mr Ogilvie Thompson said yesterday.
Nicky Oppenheimer, the chairman of De Beers who will become a non-executive director of Anglo American, said it was time for the company to bring its structure up to date in order to take on rival mining groups such as Rio Tinto.
"There always comes a time when it is right to leave home and challenge the best in the world at large. I believe that time is now," said Mr Oppenheimer.
The news was received with consternation in South Africa, where it was seen as a political snub to President Nelson Mandela's government, even though it had received the approval of South Africa's Reserve Board.
Anglo American's departure is also a blow to the Johannesburg Stock Exchange, which will lose its largest single constituent, although the company will retain a secondary listing in South Africa.
Last year Billiton, the mining group, listed in London after being demerged from its South African parent, Gencor.
Mr Ogilvie Thompson defended the move, arguing that a London listing would give the group better access to new capital, allowing it to exploit new business opportunities around the world.
Anglo American also hopes that the attention of international investors, combined with a more transparent corporate structure, will erode the large discount to value of the group's net assets at which its shares have traditionally traded.
The combined net assets of Minorco and Anglo American are likely to be worth around $15bn (pounds 8.8bn).
"If we can achieve this and handle it properly we can bring new funds, new investment and new expertise back to South Africa," Mr Ogilvie Thompson said, adding that the group would be hanging on to most of its current investments in the country.
Shares in Anglo American and Minorco have fallen sharply this year as commodity prices have collapsed following the upheaval in Far Eastern economies.
Anglo American is offering Minorco shareholders two shares in the new company for each Minorco share, with an alternative offer of $16 in cash.
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