SHANGHAI: Lead miner Western Mining Co said net profit in the first six months of this year plunged 90 percent, after it incurred hedging contract losses of 100 million yuan.

The company said in its preliminary first-half earnings report to the Shanghai Stock Exchange that the losses were largely due to the sudden turnaround in non-ferrous metal prices in the second quarter, but did not disclose any further details.

Analysts speculate that the company's hedging losses were from its wrong bets on electrolytic aluminum futures contracts.