BMA said the additional capacity would be achieved via a staged process and would include the debottlenecking of existing process plants and an increase in overburden stripping capacity.

BMA public affairs manager Ian Dymock said BMA would achieve the increased output within 12 months.

No operational changes will be made at underground operations to meet the greater output demand, with most of the adjustments made at the final end of the chain. This includes upgrading coal processing plants and streamlining loading and unloading times.

BMA secured additional rail capacity late last year and additional port capacity at the Dalrymple Bay Coal Terminal, and is also reviewing further options to increase both mine and port capacity. The majority of the increased output will be shipped through the Hay Point terminal.

BMA is an equal joint venture between BHP Billiton and Mitsubishi Development which owns and manages seven Bowen Basin coal mines and the Hay Point coal export terminal in Central Queensland. The mines are Blackwater, Goonyella, Peak Downs, Saraji, Norwich Park, Gregory and Crinum.

In addition, BMA manages and markets coal for two other mines - Riverside and South Walker Creek - on behalf of BHP Mitsui Coal Pty Ltd. Participants are BHP Billiton (80%) and Mitsui and Co (20%).

The mines have a capacity to produce over 50 million tonnes of coal annually, comprising high quality coking coals, weak coking coals, PCI coals and thermal coals, which are sold to 72 customers in 24 countries.