Monadelphous Group has signed three Queensland gas contracts with the Australia Pacific LNG Project, worth $250 million in total.
In a statement, the engineering firm said the largest contract is to construct an upstream gas processing facility.
The other contracts include the construction of a pipeline compression facility and an interconnect facility.
Work is due to be completed in line with the project's plans to deliver first LNG in mid-2015.
The Australia Pacific LNG Project is a joint venture between Origin Energy, Conoco Phillips and Sinopec.