* AMCU is now dominant union on S.Africa's platinum belt
* Disciplined union shows it can shut mines at short notice
* Rival union NUM may be shifting to the left in response
By Ed Stoddard and Sherilee Lakmidas
JOHANNESBURG/MARIKANA, March 7 (Reuters) - The bloody first round of South Africa's mine union turf war is over and the clear winner on the platinum belt is the Association of Mineworkers and Construction Union (AMCU).
From this position of strength, AMCU is signalling a radical departure from tactics used last year, when it poached tens of thousands of disgruntled members from the once-dominant National Union of Mineworkers (NUM) in a recruitment drive that triggered lethal violence and shut major mines for months.
AMCU has a well-earned reputation for militancy and its explosion onto the South African labour scene last year often appeared anarchic, marked by shantytown riots and illegal strikes that lasted for weeks.
The violence that resulted included the killing of 34 striking miners by police near the Marikana mine run by platinum producer Lonmin in August last year.
AMCU's 2013 model looks very different: with most unionised workers in the platinum belt now flying its colours, it is displaying remarkable discipline, orchestrating brief mine closures to show its displeasure at management moves.
The message is ominous for investors and boardrooms in Africa's largest economy, especially as the mid-year start of wage talks across most of the mining sector draws near.
The big platinum producers such as Anglo American Platinum (Amplats) and Impala Platinum face a vastly different labour landscape than they did two years ago.
The AMCU's message is: we are in control and can stop and restart your operations at the drop of a hat.
Just provoke us.
In January, AMCU activists said they would shut down shafts if Amplats, the world's top producer of the precious metal and a unit of Anglo American, announced job cuts in a long-awaited plan to restore profits.
Both sides acted exactly as they said they would.
Amplats said it planned to mothball two mines, sell another and slash up to 14,000 jobs as its margins sink into the red, posting its first ever loss last year.
The night of the announcement, workers at Amplats' operations around the platinum hub of Rustenburg downed tools - just for a day, but the message had been crystal clear.
This week Lonmin hosted a media tour in a bid to show, among other things, how it had put last year's crippling labour unrest behind it.
AMCU was having none of it.
It staged a one-day illegal strike on Tuesday at Marikana shafts, saying it wanted the closure of rival union NUM's offices there, because it was now the biggest kid on the block.
Visiting journalists got diverted to another shaft at the last minute.
The strike ended the next day - after the journalists left.
South Africa is by far the world's biggest producer of the precious metal used to build emissions-capping catalytuc converters and sits atop about 80 percent of known reserves.
The so-called platinum belt remains a flashpoint of social and labour tension after it was the scene of riots last year and widespread intimidation by AMCU as it recruited workers angered at the NUM leadership, which they see as out of touch with the rank and file and too close to the ruling African National Congress.
Relentless poverty in the shantytowns around the platinum mines remains a source of simmering fury.
AMCU shift boss Phahla Mekela told Reuters on Tuesday during the mine visit that the union's aim was to make a real difference to the lives of its members.
"AMCU is doing well since the strike (last year). We realise that we can't always say things to management but what we can do is act," he said, alluding to the union's new-found ability to mobilise its members at the spur of the moment.
NUM managed for years to get above-inflation wage rises for its members but did not push for increases that the companies simply could not afford.
AMCU members, who wear drab-green T-shirts see the world differently, through a red political lense that contrasts with the more pragmatic stance taken by the NUM.
The union's members are stridently anti-ANC but its leadership stresses it is apolitical - although its actions have political implications because the NUM is a key ally of the ruling party and each mineworker has around eight dependents.
So every lost NUM member is a potential loss of several ANC votes and this helps explain an outspoken stance from the government and the ruling party to demonstrate their concern over Amplats' planned job cuts.
The ANC said the move justified a review of mine licences and the party's secretary-general Gwede Mantashe, an ex-NUM leader, said "Anglo had stolen our money."
The NUM may also be shifting left to protect its members.
Diversified miner Exxaro, which supplies coal to power utility Eskom, has suspended operations at two mines after NUM workers embarked on an illegal strike over bonus payments, the company said on Thursday.
The problem for AMCU, now that the union has tens of thousands of new members including 40 percent of Amplats' labour force and the majority at Lonmin, is that rank and file expectations have been raised.
If AMCU finds it can't deliver on its promises, its tactics could change again. Or it could lose control of its members.
Neither scenario will be good for the companies, production or the wider economy, which was hit by credit downgrades last year sparked in part by the labour violence AMCU set off.