Johannesburg - South African output of platinum-group metals sank the most on record in May after a strike halted production at the world’s three biggest producers.

Production of the metals plunged 49 percent from a year earlier as total mining output fell 6.5 percent, Juan-Pierre Terblanche, a spokesman for Pretoria-based Statistics South Africa, said by phone today.

That was the biggest decrease in platinum output since the agency started keeping records in July 1994.

A five-month strike by more than 70,000 miners at Anglo American Platinum, Impala Platinum and Lonmin cost the companies 23.9 billion rand in revenue and workers 10.6 billion rand in wages by the time it ended on June 24.

The stoppage pushed South Africa’s economy into contraction in the first three months of this year as production plunged in the country that accounts for more than two-thirds of global mined supply of the metal.

The performance of South Africa’s mining industry will probably remain volatile in the months ahead, economists at Nedbank said in an e-mailed note.

“The persistent weakness will have a negative impact on second-quarter gross domestic product growth,” they said. - Bloomberg News