The world's biggest exporter of coking coal will shut down a key mining project in New South Wales on the grounds of bloated costs and want of profitability.

The Anglo-Swiss commodities giant announced that it will close the Ravensworth underground coal mine in the Hunter Valley by this September on the grounds of want of profitability. In an official statement Glencore Xstrata imputed the suspension of operations at the mine to burgeoning costs, ailing prices for coal,the high…