* Amplats fires 12,000 wildcat strikers
* Local NUM leader shot dead near Lonmin
* "Platinum belt" death toll nears 50
* Rand falls as labour unrest spreads
* Shell declares "force majeure"
(Adds NUM local leader killed)
By Agnieszka Flak JOHANNESBURG, Oct 5 (Reuters) - South Africa's Amplats
fired 12,000 wildcat strikers on Friday, a high-stakesattempt by the world's biggest platinum producer to push back ata wave of illegal stoppages sweeping through the country'smining sector and beyond.
Later on, a trade union leader was shot dead near a mine runby platinum producer Lonmin in a potentiallyexplosive escalation of the two-month-old violent labour unrestthat took the death toll to 49.
National Union of Mineworkers (NUM) spokesman Lesiba Seshokasaid the NUM branch leader had been killed "execution style" inthe evening but gave no further details.
A six-week stoppage at Lonmin in August and Septembererupted out of a turf war between the NUM and the more militantMineworkers and Construction Union (AMCU), which accuses the NUMof acting for its government allies rather than its members.
The hefty hikes won by workers from that saga has been a redrag to others while anger has been stoked by the killing of 34miners in a hail of police bullets outside Lonmin's Marikanamine in an incident that evoked apartheid-era shootings.
The sackings at Amplats (Anglo American Platinum) on Fridaytriggered a sharp fall in South Africa's rand as investorsdumped the country's assets.
The rand fell as much as 4 percent to 3-1/2 yearlows after Johannesburg markets closed, adding to the mountingtoll inflicted on Africa's biggest economy.
Strikes have spread beyond the mining sector, with Shellsaying on Friday it would not be able to honour contracts todeliver fuel near Johannesburg because of a trucking strike.
The unrest is causing political trouble for President JacobZuma and his ruling African National Congress (ANC), the veteranliberation movement with long-standing ties to labour unions.
"You fire 12,000 people, and it's like 'Oh my god, whathappens now?'" one Johannesburg-based currency strategist said.
When rival Impala Platinum fired 17,000 workers onan illegal strike rooted in the NUM/AMCU struggle, it led to aviolent six week stoppage in which the company lost 80,000ounces in output and platinum prices jumped 21 percent.
The wage deal that followed the killings at the Marikanamine in August triggered copycat demands in gold and iron ore.
"Amplats had been giving signals that it was going to holdthe line after Lonmin had folded - but it's a huge gamble," saidNic Borain, an independent political analyst.
"Someone had to take it on the chin or this would have kepton unravelling and spread through the economy. It's difficult toknow whether this causes the unrest to spread or whether ittakes some of the sting out of it. It could go either way."
Speaking to South Africa's e-News television channel, onedismissed worker said Amplats was "starting a war".
ZUMA UNDER PRESSURE
The ANC Youth League, a fierce critic of Zuma, lashed out atAmplats, which it said "has made astronomical profits on theblood, sweat and tears of the very same workers that today thecompany can just fire with impunity".
"Amplats is a disgrace and a disappointment to the countryat large, a representation of white monopoly capital out oftouch and uncaring of the plight of the poor," it said.
Zuma tried to put a positive spin on the situation in aspeech to business leaders late on Thursday, stressing thatsince the end of white-minority rule South Africans have shown"the capacity to overcome difficulties when we work together".
"We should not seek to portray ourselves as a nation that isperpetually fighting," he said.
However, with an ANC leadership run-off looming in December,Nelson Mandela's 100-year-old liberation movement is preoccupiedwith its own divisions. Zuma is seen as unlikely to take anyaction that could upset his political allies in the unions.
"In the build-up to the election, the government is unlikelyto come out with any clear policy directives," said SimonFreemantle, an analyst at Standard Bank in Johannesburg.
Reflecting such concerns, Moody's cut South Africa's creditrating last week. Finance Minister Pravin Gordhan has alreadysaid he will have to cut his 2.7 percent growth forecast for2012 when he delivers an interim budget on Oct. 24.
More than 75,000 miners, or 15 percent of the workforce in asector that accounts for 6 percent of output, have been out onunofficial strikes, and tensions with security forces and miningbosses were running high even before the mass Amplats sackings.
Near the "platinum belt" city of Rustenburg, 120 km (70miles) northwest of Johannesburg, workers said a miner waskilled by a rubber bullet fired by police on Thursday night.
Police would not confirm the cause of the death, althoughthe ground nearby was strewn with spent rubber-bullet shellcasings and teargas canisters after clashes the previous night.
On Friday, protesters in a shanty town near the Amplats minebarricaded streets with rocks and burning tyres as more than 30riot police backed by armoured vehicles stood nearby.
AngloGold Ashanti , South Africa's biggest bullionproducer, has lost virtually all local production due to wildcatstrikes, while rivals Gold Fields and Harmony Gold
have also taken a hit. Around 300 strikers at KumbaIron Ore have also blockaded the company's giant Sishenmine in the remote Northern Cape province.
Apart from the mining sector, a strike with more potentialto damage the wider economy is brewing in transport, with 20,000truckers on a two-week authorised stoppage to demand higher pay.
Shell said on Friday it could not honour fueldelivery contracts around Johannesburg, declaring "forcemajeure" to free itself and customers from existing obligations.
"There is fuel available across the country, so the issue isnot fuel supply, but the challenge is delivering it safelyto our retail sites," the oil major said. Other petrol companiesare holding their breath, especially around the commercial hubJohannesburg, but have not yet followed Shell's move.
Raising the stakes, transport union SATAWU said it wantedworkers at railways and ports to strike next week, a developmentthat would affect coal and other mineral shipments.
(Additional reporting by David Dolan, Wendell Roelf, StellaMapenzauswa and Ed Stoddard; Writing by Ed Cropley; Editing byPeter Graff and Philippa Fletcher)
Keywords: SAFRICA STRIKES/