JOHANNESBURG (Reuters) - South Africa's National Union of Mineworkers is giving diamond producer De Beers, a unit of Anglo American, a 48-hour strike notice after mediation failed to resolve a wage dispute, NUM General Secretary Frans Baleni told Reuters on Wednesday.
Baleni said the "strike will likely commence on Sunday or Monday but we are open for negotiations to avoid the strike." De Beers said in a statement it could also lock out union members.
Labor unrest and wildcat strikes have rocked the platinum and gold sectors periodically over the past 18 months in Africa's largest economy, with the violence rooted in a turf war between NUM, which was once unrivalled, and the upstart Association of Mineworkers and Construction Union (AMCU).
But NUM's dispute with De Beers is following legal channels and so is unlikely to unnerve jittery investors who are more focused on upcoming wage talks in the gold, platinum and coal sectors which are seen as among the toughest ever.
AMCU refused to sign a government-brokered stability pact on Wednesday aimed at defusing tensions in the mining industry ahead of those talks.
In the case of NUM and De Beers, the talks went to mediation after the union dropped its wage hike demand to 13 percent from 17 percent while the company stuck to a 6 percent offer.
De Beers said there had been agreement on "the broader issues in the wage negotiation" but no deal could be reached on other, unspecified demands.
De Beers produced 4 million carats of diamonds in South Africa last year, out of the total of 27.9 million carats it produced worldwide.
(Reporting by Ed Stoddard; Editing by David Evans and Jim Marshall)