South Africa's Amplats says NUMSA union signs wage deal

* Amplats signs agreement with NUMSA union

* Wage hikes of 8.5 percent for 2,500 workers

* AMCU continues strike (Adds details)

JOHANNESBURG, March 20 (Reuters) - Anglo American Platinum said it signed a wage agreement with the National Union of Metalworkers of South Africa (NUMSA) on Thursday, ending a six-week strike, with no end in sight to a longer stoppage by another larger union.

The agreement will see wage increases of up to 8.5 percent for the members of NUMSA.

The Association of Mineworkers and Construction Union (AMCU), by far the largest union at Amplats' operations, is still on an eight-week strike that has cost companies and workers billions of rand in lost revenue and wages.

NUMSA represents about 2,500 workers at Amplats who work mainly in the company's smelters.

Amplats spokeswoman Mpumi Sithole said NUMSA workers would return to work on the Thursday night shift but the AMCU strike rumbles on.

Talks have collapsed between AMCU and the world's top platinum producers - Amplats and two rivals, Impala Platinum (Other OTC: IMPUF - news) and Lonmin (Frankfurt: LRH.F - news) - over the union's demands for a more than doubling of entry-level wages over the next three years, which the companies say they cannot afford.

Amplats and its peers have offered increases of up to 9 percent to AMCU, the biggest union by far on South Africa's platinum belt.

"The increases on offer are already significantly above the current inflation rate and therefore the company encourages AMCU to also accept the current offer," Amplats said.

The AMCU strike is the biggest on the mines since apartheid rule ended in South Africa in 1994 and has cost the companies over 9 billion rand ($825 million) so far and counting in lost revenue. [ID: nL6N0ME4LU]

($1 = 10.9317 South African Rand) (Reporting by Zandi Shabalala; editing by Ed Stoddard)