GLENCORE will shut down its Australian coal operations for three weeks across Christmas in response to continued weak global demand.

The move, which will cut the Swiss giant’s coal output by about 5 million tonnes, came as thermal coal prices hit the low US$60s last month, more than half the heights reached three years ago.

In a statement, Glencore said the decision was made given the current oversupply situation and would reduce the need to push sales into an already weak pricing environment.

However the company said it believed the market would strengthen in time. “We remain confident in demand growth for our products and believe that the supply and demand balance will be restored in the medium term,” it said.

More than 8500 workers at Glencore’s 20 coal mines across NSW and Queensland will be forced to take the time as annual leave, prompting an angry rebuke from the Construction, Mining, Forestry and  Energy Union (CFMEU) about a lack of consultation with workers.

“Glencore’s decision to spring this on workers with only a month’s notice will catch some workers short of annual leave and force them to change holiday plans,” CFMEU national president Tony Maher said.

“Growing casualisation in the industry means the shutdown will be a disaster for labour hire workers who will simply be told they’re not needed over Christmas.” However the union welcomed the move to take supply out of the market.

“We urge all coal mining companies to consider ways to look at ways they can reduce production and tackle the oversupply damaging the industry,” Mr Maher said.