After February's trading update, these full-year figures from Kazakh copper miner Kazakhmys (KAZ) contained few operational surprises. Yet the shares still slumped around 10 per cent on the day the figures appeared - significantly reflecting a $2.2bn (£1.45bn) impairment charge taken against the group's 26 per cent stake in Eurasian Natural Resources Corporation (ENRC), which saw its shares slump during 2012.
Kazakhmys' revenues actually held up reasonably well, despite the copper price fall and a 4 per cent reduction in sales volumes. However, a 25 per cent rise in the cost of sales meant that operating profit fell to $368m from $1.22bn in 2011, while the ENRC impairment explains the hefty headline loss. Operationally, a 12 per cent rise in ore output was offset by a fall in grades, which resulted in overall copper production falling 2 per cent to 294,000 tonnes.