It has long been speculated that Anglo might increase its stake in De Beers, which vies with Russia's Alrosa for dominance in the diamond mining industry.
Finance Minister Alexei Kudrin told reporters in Washington, DC this weekend that he will vacate his chairman post next week at VTB Bank and diamond miner Alrosa.
For Alrosa, which is desperately short of investment, the three-year deal means that the company may be able to return to world markets to try and raise additional finance.