The world's-biggest mining firm BHP Billiton said on Thursday that one of the two potlines at its Mozal aluminium smelter in Mozambique had been shut down for 40 minutes on Wednesday evening due to loadshedding by Eskom, and that it had also already experienced power supply interruptions at all its Hillside and Bayside aluminum smelters in Richards Bay.

Speaking in a telephone interview, spokesperson Bronwyn Wilkinson said that all the interruptions so far had been in line with the resource giant's contracts with State-owned power utility Eskom.

"We stay in contact with them all the time to minimise the effect on production," she said.

However, she stated that the power cuts did affect production, but said that BHP Billiton would not disclose by how much.

"It's not material at the moment," Wilkinson commented.

Asked if BHP Billiton expected further load shedding in the coming winter months, she replied "I would imagine so".

On Monday night and Tuesday night, Eskom, Africa's biggest electricity supplier, had experienced record levels of deman, and said that its reserve margins were growing narrower.

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