Rio Tinto Limited
(ASX:RIO) is facing a battle with unions over a contract dispute in the Canadian province of Quebec.
The global miner has reportedly told Reuters it will shut down about a third of the production at its Alma aluminum smelter after locking out hundreds of unionised workers.
Rio says it has been negotiating with the union since October 4, 2011 ahead of contracts expiring at the end of last year.
The shutdown is understood to now have started.
Rio Tinto reported a net profit of $7.5 billion in the first half of the 2011 calendar year.
