Anglo American posted an annual loss of $3.1 billion on Thursday after taking an impairment of $3.8 billion, mostly due to its ailing diamond unit, as it races to restructure into a major copper producer following a bruising takeover battle with BHP last year.

The miner wrote down the value of its embattled diamond business again as it seeks to ready the division for disposal.

Anglo American has written down the value of its De Beers diamond business for the second time in two years. The London-listed miner said on Thursday it had booked an impairment charge of $2.9bn on the unit,

Anglo American posted a $3.1 billion loss on Thursday, dragged lower by a De Beers diamond unit writedown, and pared its dividend, while the market welcomed its progress towards asset sales and reduced debt.

The diversified miner posted a worse loss than expected as it booked billions of dollars worth of net impairments.

Anglo American Plc took another writedown on its struggling De Beers diamond unit, and posted a slide in profit, as the miner moves ahead with a radical overhaul of its business.

Anglo American (OTCQX:AAUKF) (OTCQX:NGLOY) said Thursday it wrote down the value of its struggling De Beers diamond business by another $2.9B, after already writing down the business by $1.6B to $7.6B last year.