Kazakh miner ENRC has taken $1.5 billion of charges because of weak aluminum prices and a hit to the value of its operations in Africa, dragging the business to a loss in 2012.
London-listed ENRC, which warned last month that it would take a "significant" writedown, said on Wednesday that the impairment charge totaled $1.2 billion. It also took a $328 million provision due to a now-unprofitable alumina supply contract with Russia's RUSAL.
The company posted a 45 percent drop in core profit - earnings before interest, tax, depreciation and amortization — to $1.89 billion.
The company posted a basic loss per share of 62 cents, compared with earnings per share of $1.53 in 2011.
It also scrapped a final dividend payment, leaving a full-year payout ratio of 16 percent, based on its interim dividend.