Hunter Valley Energy Coal goes down under for coal. The company produces about 12 million tons of thermal coal through its primary operating mine, the Mt Arthur coal mine in New South Wales, Australia. Hunter Valley Energy is also working on expanding the Mt Arthur project, through expanding the existing surface mine and adding an underground project as well. It is a subsidiary of BHP Billiton's Energy Coal segment, which maintains other coal operations in Africa and the Americas. The company is able to make use of BHP Billiton's marketing hubs in Singapore and the Netherlands.