* Toyota's Durban plant hit by four-day walkout
* Three more Amplats mines closed; police fire tear gas
* Kumba Iron Ore stops output at giant Sishen pit
* Talks to end truck drivers' strike collapse
* Zuma under pressure before ANC leadership vote
(Adds union comment, Amplats closures and violence)
By Wendell Roelf
CAPE TOWN, Oct 4 (Reuters) - Toyota Motor Corp
it had been forced to shut its South African car factory for four days because of an illegal pay strike, the first sign of wildcat mine stoppages spreading into other parts of Africa's biggest economy.
Union leaders at the Japanese car giant's Durban plant said workers would return on Friday after winning a 5.4 percent pay rise inspired in part by a hefty increase won last month by strikers at Lonmin's
Marikana platinum mine.
"The circumstances are not the same as what is happening in the mines," said Mbuso Ngubane of the National Union of Metalworkers of South Africa (NUMSA).
"But it does send a message. It does have an impact to some extent on other workers getting agitated."
After two months of unrest, at least 75,000 miners, or 15 percent of the sector's workforce, are on strike, burdening already sluggish growth only three months before an internal leadership vote in the ruling African National Congress (ANC).
President Jacob Zuma is favourite to win re-election, teeing him up for a second five-year term as South African president in 2014, but the turbulence strengthens the hand of those who say he is unfit to run a sophisticated emerging economy.
On Thursday, Kumba Iron Ore
, one of the world's top 10 producers, said it had suspended production at its huge Sishen mine after striking employees blocked access to the pit.
Wildcat industrial action at the world's top platinum producer Anglo American Platinum (Amplats)
also spread from its four mines near Rustenburg, 120 km (75 miles) northwest of Johannesburg, to three mines 100 km farther north, a union said.
Local radio said police had fired tear gas near Rustenburg on Thursday at striking Amplats miners, who were hurling stones.
The seven plants account for a quarter of global supply of the precious metal, whose price has risen more than 22 percent since the Aug. 16 police killing of 34 strikers at Marikana - the bloodiest security incident since the end of apartheid.
Overnight, police said suspected wildcat strikers had burnt down two conveyors and a training centre at an Amplats mine in Rustenburg.
Meanwhile talks to end a legal strike by more than 20,000 truck drivers collapsed after unions rejected an offer of an 18 percent pay rise over two years, the Road Freight Employers' Association said.
Fuel suppliers are having to use police convoys to prevent drivers being attacked by gangs trying to enforce a blockade that is putting petrol stations at risk of running dry.
Although South Africa's racially polarised labour market is prone to industrial action, the aftermath of the so-called "Marikana massacre" has blown apart normal negotiating procedure and exposed the weakness of established unions.
The Congress of South African Trade Unions (COSATU), a close ally of the ANC, is in talks with the big mining houses to try to stop the strikes.
"This, we hope, will save collective bargaining, save the industrial relations in the country while at the same time bringing workers and their demands on board," COSATU General Secretary Zwelinzima Vavi said.
But COSATU is making little headway after losing much of its influence in the last 12 months.
"You are going to see quite a lot more of these wildcat strikes," said Chris Hart, chief strategist at asset managers Investment Solutions.
"Despite there being a whole lot of issues which are separate and distinct from Marikana, there is a sense that if you go on the rampage outside the collective bargaining system you get more benefits."
Fallout from the unrest in the mines, which account for 6 percent of GDP, has put pressure on the rand
, which has fallen towards a three-year low against the dollar.
It has also fuelled concern about growth, forecast by the government at 2.7 percent this year.
Manufacturing makes up 15 percent of South Africa's output, and widespread factory walkouts could have dramatic implications for the economy, especially with exports already suffering from economic woes in Europe, their main destination.
Major bullion producers AngloGold Ashanti
and Gold Fields
have also been hit by strikes.
Despite its shut-down, Kumba Iron Ore, a unit of Anglo American, said it had sufficient stockpiles and output from other mines to supply customers for "some time". Sishen mine produced nearly 40 million tonnes of iron ore in 2011.
(Additional reporting by Agnieszka Flak, Ed Cropley, Ed Stoddard and Sherilee Lakmidas; Writing by Ed Cropley; Editing by Kevin Liffey)
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((For a graphic on the rand:
Graphic on mining sector wages:
)) Keywords: SAFRICA STRIKES/