* Lonmim management, workers press on with wage talks
* No. 1 platinum producer Amplats silent on Rustenburg ops
* Activist says most Amplats workers there still off the job
JOHANNESBURG, Sept 18 (Reuters) - Striking South African miners at platinum group Lonmin cut wage demands in their six-week stoppage, while the top world producer of the precious metal, Amplats, was silent on Tuesday on whether it had been able to resume operations suspended in the unrest.
The government, mediators and mining companies have intensified efforts to resolve the mining sector troubles which have hit the rand currency, raised insurance against default on South African debt and spooked some foreign investors into selling shares in mining companies.
Strikers at Lonmin's Marikana mine 100 km (60 miles) northwest of Johannesburg scaled back their basic demand to under 11,000 rand ($1,300) a month, still way above the latest offer from the world's No. 3 platinum producer.
The company, which is offering increases of between 9 and 21 percent, has said 12,500 rand would put thousands of jobs at risk and challenge the viability of the business.
A Lonmin official said talks between the various parties had resumed at mid-day on Tuesday after an overnight session.
"The demands came down to below 11,000 rand," Bishop Jo Seoka, who has been mediating in the talks between Lonmin and workers, told Reuters.
Lonmin's acting chief executive Simon Scott told Reuters he could not say when the strike would end. "I can't give timelines. Negotiations have to be conducted in good faith and at the moment that's what we're doing," he said.
QUESTIONS OVER AMPLATS RESTART
The strike at Marikana turned violent last month, culminating in the police shooting 34 miners at a rocky outcrop near the mine. In all, 45 people have died in the Marikana unrest, which has spread beyond Lonmin to other platinum firms around Rustenburg and other parts of the mining sector.
Anglo American Platinum (Amplats), the world No. 1 producer, said workers had started trickling back to its Rustenburg mines on Tuesday after operations were suspended last week when machete-wielding strikers marched on shafts.
But the company did not say if its Rustenburg operations had been able to restart as it had announced late on Sunday.
A local labour activist and community representative said most Amplats' workers in the Rustenburg area had stayed away.
"The overwhelming majority of the workers did not report back to work," Mametlwe Sebei, a member of the Rustenburg miners' strike committee, who also belongs to the Marxist fringe party, the Democratic Socialist Movement, told Reuters.
It was not possible to verify his comments independently.
South Africa is home to 80 percent of known reserves of platinum and is a major gold producer. The labour unrest this year has cost the mining industry 4.5 billion rand ($548 million) in lost output, President Jacob Zuma said on Monday.
Fearing the strike's growing impact on the economy and South Africa's investment reputation, the government launched a crackdown at the weekend that has included deploying members of the armed forces to back police against violent strikers.
Officers seized weapons and dispersed some protesting Marikana workers with tear gas and rubber bullets.