The National Union of Mineworkers, which represents 64 percent of gold miners in South Africa, plans to start a strike over pay from the nightshift of Sept. 3, the Chamber of Mines said.

The strike will affect workers at companies including AngloGold Ashanti Ltd., Sibanye Gold Ltd., Harmony Gold Mining Co. and Gold Fields Ltd.

“The employers will continue to make plans in anticipation of strike action to ensure the continuation of essential services,” the Johannesburg-based industry body said in an e- mailed statement today. “Employers remain open to discussions.”

The Chamber has offered to boost pay by between 6 percent and 6.5 percent for about 142,000 workers covered by the talks while the NUM wants starting salaries increased by as much as 60 percent. Other unions operating in the industry have also rejected the pay offer while they are yet to serve a strike notice.

South Africa is Africa’s biggest gold producer.