Shareholders in Anglo American, the diversified mining group founded by De Beers’ former chairman, Sir Ernest Oppenheimer, are reportedly urging the corporation to purchase the 40 percent stake in De Beers that is currently owned by the Oppenheimer family. Anglo American already owns 45 percent of De Beers.

According to London’s Observer newspaper, analysts consulted by the shareholders suggest that the Anglo the stake is undervalued, because De Beers, which today is no longer publicly listed, is difficult to evaluate. Its total worth is estimated to be between $17 billion and $18 billion.

The remaining 15 percent in De Beers is held by the government of Botswana, which itself jointly owns with De Beers the Botswana mining company Debswana, which is De Beers’ largest producer of rough diamonds.

In its article the Observer noted that in recent years De Beers has been providing the market with more information about its affairs. This the newspaper says has led to speculation that the mining company may be considering an initial public offering (IPO).

A De Beers official close to the Oppenheimers said that the family was "happy at the moment with its holding in the company.” But, said the Observer, analysts both in London and Johannesburg are skeptical as to whether the ownership structure at De Beers will remain in place for long.