UPDATE 1-Union says 4,000 workers on strike at Simmers mine

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JOHANNESBURG, Jan 14 (Reuters) - South Africa's National Mineworkers Union (NUM) said on Wednesday about 4,000 workers at Simmer and Jacks Mines' (SIMJ.J) Buffelsfontein mine were on strike over pay and possible job cuts.

"We are presenting a memorandum of our demands to management at the moment. The management is playing hide and seek on the wage negotiations and other issues regarding the retrenchments," NUM regional organiser Elros Mphahlele told Reuters.

He said the workers were demanding a 30 percent wage rise, while management was only offering a 5 percent hike. The wage talks were supposed to have been completed by Dec. 31.

Simmers said in November it could lay off about 500 workers at the Buffelsfontein Gold Mine (BGM) by the end of January if it failed to meet output targets.

The company said it faced unprecedented increases in the costs of mining and milling materials, while it had spent large amounts of capital since 2005 to ensure that the mine had the infrastructure to produce according to plans.

Company officials were not available for comment. (Reporting by Muchena Zigomo; editing by Sue Thomas)