Johannesburg - The National Union of Mineworkers (Num) said on Wednesday it had served De Beers Consolidated Mines with a strike notice after wage talks between the two parties had failed. The union said it was asking for a 15% rise in wages, while De Beers is offering 7.5% and a once off payment of R2 500. “The offers are totally unacceptable to us. We totally reject these,” said Peter Bailey, the Num’s chief negotiator at the company. Unlisted De Beers is 45% owned by mining firm Anglo American [JSE:AGL].