Escondida, the world's largest copper mine located in northern Chile, produced 520,899 metric tons of copper in the first half of 2009, down 28% from the 725,177 tons in the same period last year, the mining company said Friday.

The drop was due to falling ore grades at the mine and production problems associated with its Laguna Seca SAG mill concentrator, which resulted in the plant operating at a lower capacity, Escondida said.

During the six-month period, Escondida produced 356,798 tons of copper contained in concentrates, down 41% from the same period a year earlier.

The company said that copper cathode production, however, rose 34% to 164,101 tons due to "improved recovery and an increase in the level of activity and ore accumulation in the process stockpiles."

In the first half, Escondida posted a net profit of $1.1 billion, down 73.2% on the year.

In the six months ended June 30, the average price per pound of copper on the London Metals Exchange was $1.84, down 50.1% from the average $3.68 recorded for the same period in 2008.

Escondida is controlled and operated by diversified global miner BHP Billiton Ltd. (BHP), which has a 57.5% stake. Anglo-Australian mining company Rio Tinto PLC (RTP) holds 30% of Escondida, with an additional 10% held by a Japanese consortium led by Mitsubishi Corp. (8058.TO) and the remaining 2.5% by International Finance Corp.(IFC.KW), the private-sector unit of the World Bank.

Minera Escondida is an open pit mine located 170 kilometers southeast of Antofagasta, at 3,100 meters above sea level.

-By Julian Dowling, Dow Jones Newswires; 56-2-820-4241; julian.dowling@dowjones.com