The plant, which produces about 250 000 tonnes of copper per year, is one of the biggest processing facilities in Africa's second-largest copper producer.

Zambia generates about 87% of its electricity from hydropower, and lower water levels due to its current drought, the worst in two decades, have curbed power generation, the managing director of State-owned power utility Zesco said.

Zesco said last week it would start rationing electricity supplies from March 11. However, the sources said that Chambishi had already reduced capacity as of last week.

CNMC did not immediately respond to emailed questions on the matter. The company is now considering plans to install diesel generators at the plant to help alleviate the impact of power shortages, according to the sources.

The power shortage comes amid a gradual decline in Zambia's copper production due to lack of new investment at some operations, including Konkola Copper Mines and Mopani Copper Mines.

--Reuters--