South Africa's NUMSA union says reverting to 15 percent wage demand

JOHANNESBURG (Reuters) - South Africa's striking engineering and metal workers union NUMSA said on Tuesday it was reverting to a demand for a 15 percent wage increase, because employers had failed to respond in kind to its concession of a lower 12 percent. "Even after we had moved to 12 percent, employers didn't make any or movement or better offer," National Union of Metalworkers of South Africa (NUMSA) spokesman Castro Ngobese said. "Since the negotiations have collapsed we must revert back to our initial demand." (Reporting by Stella Mapenzauswa; editing by David Dolan)