The South African group, which mines 40% of the world’s diamonds, said it was confident it could survive two more years of recession.

Stuart Brown, finance director, said: “Trading conditions are tough, but because we saw it early and took very dramatic steps around the business, we are in a position to weather trade in 2009 and 2010 without any recourse to shareholder funds.”

De Beers disputed an estimate by Barclays Capital that it lost £68.1m in the first quarter this year. Fourth quarter sales slowed significantly, but full-year underlying earnings rose by 7%.