De Beers returned to a profit in 2010 as diamond production rose 34 percent and diamond prices recovered to pre-crisis levels, although it remains cautious about the market this year, Reuters reported.

It posted net earnings after one-off items of $598 million, compared with a net loss of $220 million in 2009, after recovering a better-than-anticipated 33 million carats as average diamond prices rose 27 percent, said the report.

De Beers had targeted production of about 30 million to 31 million carats for 2010, it said.

"The price of rough diamonds has recovered strongly as confidence returned to most parts of the diamond pipeline," the company said. "Notwithstanding this, the industry is not back to pre-recessionary levels in terms of production or sales and a high degree of global uncertainty remains."

De Beers said on Friday it plans to increase production to 38 million carats this year and approach full production of around 40 million in 2012.

Anglo American which is due to report its full-year earnings on Feb. 18, said it will post underlying earnings of $302 million for the year from its investment in De Beers.

Credit Suisse said the contribution was slightly ahead of its forecast of $296 million.