Zijin Mining Group Co., China's largest gold producer, said Tuesday its first-half profit jumped by 40 percent year on year due to rising bullion prices.

Net profit was 2.71 billion yuan ($400 million) in the first half, while sales rose 39.78 percent to 13.46 billion yuan. Earnings per share were 0.186 yuan, up 39.85 percent year on year, the company said in a statement filed with the Shanghai Stock Exchange.

Zijin attributed its profit growth to the unstable economic environment and investors' demand for gold as a safety haven, which had boosted gold prices in the first half of 2010.

The gold miner also said in the statement that it lowered its gold-output target for the entire year to 30 tonnes from 31.1 tonnes, copper target by 10,000 tonnes to 90,000 tonnes and iron ore target by 120,000 tonnes to 1.18 million tonnes because waste leakage at one of its copper mines in July would affect its production in the second half.

Between 4 p.m. July 3 and 2:30 p.m. July 4, about 9,100 cubic meters of waste water spewed from a blown-out sewage tank at a copper plant owned by Zijin into the Tingjiang River in Fujian Province, killing thousands of fish.

After the toxic spill, the local government asked the company to restrict its output to reduce the environmental risks.

The mining company's shares fell 4.49 percent to 6.17 yuan per share at the close.