Under the five-year contract, Downer will provide operating and managing the mine and associated activities, including mine planning and design, overburden removal, drill and blast, coal mining and rehabilitation.

Downer will begin the mining services on 1 September 2014 and as part of the contract which is valued between $200-250m and has option for a five-year extension.

Downer chief executive officer Grant Fenn said that Downer is pleased to be continuing 14-year partnership with Millmerran Power Partners.

"It is due to the strength of our relationship with Millmerran Power Partners that Commodore has become our flagship mining project in terms of environmental sustainability," Fenn added.

"It has been one of the first open cut coal mines in the world to completely switch its total fuel use to biodiesel and has also pioneered a program to independently verify fugitive methane emissions."

Since 2000, Downer has been providing with a total mining service at Commodore to deliver coal to Millmerran Power Station.