The miner said it would examine De Beers’s value in light of sluggish demand for diamonds as it seeks to exit the business.

Anglo American Plc expects to take a writedown on its De Beers operations, as plunging diamond sales prompt output cuts and complicate its plan to exit the business.

Anglo American said all divisions met their full-year production guidance, and it expects its De Beers diamond business to book an impairment.

The London-listed miner announced Thursday that it will review De Beers’s value as it looks to exit the business, citing persistently weak diamond demand. Last year, Anglo reduced De Beers’s book value by $1.6 billion to $7.6 billion.

Mining giant Anglo American has cut forecasts for its rough diamond output over the next two years, as demand for the stones continues to wane.