Shares in miner Anglo American were tarnished this morning after it said it expects to book $3bn-$4bn in writedowns in the first half of this year, due to its iron ore operation in Brazil and some Australian coal assets.
The FTSE 100-listed company, due to report its first half results next week, attributed the impairments to "significant further weakness and ongoing volatility in the prices of the bulk commodities, particularly iron ore and metallurgical coal" in the first half.
Read more: Copper shines brightest at Anglo American
Miners have has suffered amid the global commodities slump triggered by the slowing Chinese economy - which struggled to hit the double-digit growth it saw before the financial crisis, as demand for its exports waned.
Anglo American gave mixed production update for the second quarter, with copper output up 14 per cent and nickel down 22 per cent.
While the surge in copper production beat forecasts, iron ore production slipped by one per cent, missing expectations of a slight increase.
Its shares were down 1.1 per cent to 864p in early morning trade.