The FTSE 100 Index is to lose another female chief executive after Cynthia Carroll announced she is to step down as boss of Anglo American.
Her decision to quit the mining giant, which owns Tarmac and the majority of diamond company De Beers, comes days after Dame Marjorie Scardino said she planned to stand down as chief executive of Penguin books and Financial Times owner Pearson.
The departures will leave just two female chief executives among London's top 100 public companies, with Angela Ahrendts at fashion group Burberry and Alison Cooper of Imperial Tobacco.
Ms Carroll, who took over as chief executive in March 2007, will remain in her post until a successor has been appointed.
Speculation over her position has grown in recent weeks, with some City institutions reportedly unhappy with the company's strategy, falling profitability and share price.
And delays to production from Minas-Rio, an iron ore project, have increased pressure on Ms Carroll, Sky News reported last weekend.
The American said it had been a "great honour" to lead the London-headquartered business, which has 100,000 staff and is one of the world's largest mining companies with an 85% stake in diamond firm De Beers.
She added: "It is a very difficult decision to leave, but next year I will be entering my seventh year as chief executive and I feel that the time will be right to hand over to a successor who can build further on the strong foundations we have created."
Anglo American chairman Sir John Parker said Ms Carroll's legacy included a step change improvement in safety and in the quality of the company's dialogue with governments and shareholders.
He said: "Cynthia's leadership has had a transformational impact on Anglo American."
She took over the running of Anglo American after 18 years in the aluminium industry with Alcan, including five as president and chief executive of its primary metals arm.
The appointment took the City by surprise as it was the first time that Anglo has appointed an outsider to the top job. Anglo was founded in Johannesburg in 1917 by Ernest Oppenheimer to exploit the world's biggest gold field, and it now operates in over 60 countries.