Militant union AMCU Monday served notice to strike within 48 hours at top global platinum mines in South Africa, the firms confirmed.
Leading producers Anglo American Platinum, Impala Platinum and Lonmin confirmed members of the dominant Association of Mineworkers and Construction Union will start their strike for higher wages at morning shift from Thursday.
Lonmin said attempts to "reach a sustainable resolution to the wage demands" with the Association of Mineworkers and Construction Union (AMCU) last year had failed to provide a solution.
According to union membership figures from late last year, over 80,000 workers will strike at the firms, just over half their combined workforce.
The union demands a basic salary of 12,500 rand ($1,150, 850 euro) -- more than double the 5,000 rand entry-level pay the union claims workers currently earn.
Firms say the basic wage is higher, and have offered an eight-percent increase.
The industry is still reeling from a series of wage-related stoppages from 2012 that saw AMCU muscle out the government-allied National Union of Mineworkers.