In a production update, Impala said it had lost an estimated 38,000 refined PGM ounces, nearly 3% of total refined output, owing to so-called load shedding by state power utility Eskom.

Impala's refined output declined to 1.476 million ounces in the six-month period, down from 1.617 million ounces in the same period last year.

"Smelting capacity in the period was constrained by the increased occurrence and severity of load curtailment and exacerbated by the commencement of the scheduled rebuild of the No.4 furnace in Rustenburg," Impala said.

Concentrate production was unchanged at 1.616 million ounces and the miner closed the half year with 140,000 ounces of excess inventory.

Bigger rival Anglo American Platinum on Thursday reported a 25% decline in refined PGM output last year, blaming dealys to the rebuild of its Polokwane smelter, power outages and lower mine output and grades.

Impala, which has operations in South Africa, Zimbabwe and Canada, will release its interim results on March 2.

(Reporting by Nelson Banya; Editing by David Goodman)