By Agnieszka Flak and Shapi Shacinda

JOHANNESBURG, Oct 5 (Reuters) - Investment in South Africa'smines could suffer from continued talk of nationalisation,despite government reassurances that it is not official policy,an industry leader said on Tuesday.

Sipho Nkosi, the president of the Chamber of Mines, said hismembers were delighted by President Jacob Zuma's and the miningminister's statements that nationalisation was not the policy ofthe ruling African National Congress.

But the fact that the issue was being debated was worrying,he added.

"We could never be 100 percent comfortable simply because'noises' keep on coming through from the (political) system,"Nkosi told Reuters in an interview.

South Africa's ruling ANC agreed to explore greater statecontrol of the mining sector, but made no shift in economicpolicy at one of its biggest meetings in years last month.

Zuma has been under pressure on nationalisation from unionallies and from the youth wing of his ANC, but no decision willbe taken before 2012, when the ANC holds its next major meeting.

"There is no certainty in terms of the kind of investmentsthat you can make because you don't know the outcome of the 2012report," Nkosi said. "That really causes some concern inpeople's minds."

Mine nationalisation would place an enormous financialburden on South Africa, the world's largest producer of platinumand fourth largest of gold. The influential Mail and Guardiannewspaper has estimated that the cost of such a move would be atleast $280 billion, more than double the annual state budget.

The chamber welcomed the mining ministry's decision to put asix-month moratorium on new prospecting bids in a move to reviewits minerals law after damanging disputes with two firms overrights. "There is more agency, more speed that seems to be flowingthrough the Department (of Mineral Resources) and that gives ussome comfort that these six months, even though it seems as aninterference in our processes, it may result in us getting ourlicences much quicker than we were getting them," Nkosi said.

The head of the chamber also said the industry was unlikelyto meet its target of having a safety record on par with that ofother major mining hubs in the industrialised world by 2013.

"I think we will battle to reach that target," he said.

South Africa has a dire safety record, with 165 minerskilled last year, and fatalities have led to the temporaryclosure of mines and reduced output, which is already decliningdue to falling grades.

Deaths caused by falling rocks remain a concern in thecountry, which has the world's deepest gold mines and is proneto earth tremors. (Reporting by Agnieszka Flak and Shapi Shacinda)