A South African mine workers union started a new round of talks on Wednesday with negotiators at Impala Platinum to head off a strike over wages that could impact global prices of the precious metal.

The negotiations with the world's second largest platinum producer come after unionised gold and coal workers reached deals this week for 7.5 to 10 percent wage hikes to end strikes that dented output in the global mining power.

Results from the talks are not expected until Thursday, said Eddie Majadibodu, chief negotiator at the National Union of Mineworkers (NUM), the biggest union in the mining sector.

"The negotiations are getting very tough now, so it is difficult to say where the talks will go," he said.

The NUM, seeking a 14 percent raise for its 26,000 workers at Implats, has rejected the latest offer from the company of between 7.5 and 8 percent. Unions say employers should pass along the benefits of sky-high precious metal prices to workers facing increasing food and fuel bills.

Implats and its bigger rival Anglo American Platinum together account for two-thirds of global platinum supply and any prolonged strike could push prices higher.

Economists have cautioned that wage settlements well above the current 5 percent inflation rate erode South Africa's global competitiveness by driving up the cost for a labour force that is already more expensive and less efficient than those in rival emerging economies.

The ruling African National Congress, in a governing alliance with labour, does not want to antagonise a group that has supplied it with millions of votes by putting pressure on unions to seek more modest deals.

WAGE BATTLE AT ESKOM

Gold miners started returning to work late on Tuesday after a two-year deal was reached with the country's top three gold miners. The companies said it would take a day or two before mines are back to full production.

The NUM said it had resumed talks on Wednesday with management at state-owned power utility Eskom , which supplies more than 95 percent of South Africa's electricity.

A NUM spokesman said late on Wednesday that no deal had yet been reached but the talks were to continue on Thursday if the impasse persisted.

Eskom, struggling to pay for new power plants after an electricity crunch in 2008, gave workers a 9 percent raise last year and 1,500 rand a month for housing to head off a strike when South Africa was hosting the World Cup soccer finals.

It plans to drastically raise electricity rates to pay for new plants, taking more money out of middle class paychecks.

Further wage hikes will make it more costly to hire the workers needed to bring power by 2014 to the 25 percent of the country's households that still have no access to electricity.

If Eskom gives in to union demands, its workers will have received wage and benefit increases of around 30 percent over two years.

More than 200,000 South African water, sanitation and refuse workers plan a wage strike in the coming days that could disrupt services in major cities, their union said on Wednesday.

The SAMWU union said in a statement the employers' "failure to meet the legitimate demand of the workers and their failure to improve on their previous offer at conciliation today leaves the union with no choice but to engage in industrial action."