MELBOURNE - Australia's superannuation funds should be free to support the coal industry's expansion plans, Resources Minister Keith Pitt said on Tuesday, as a battle heats up over new mines in the key Hunter Valley mining region of New South Wales.

Pitt's comments come as pressure grows on institutional investors to limit funding for new thermal coal mines as part of the global energy transition.

Australia, the world's top coal exporter, is increasingly an outlier for failing to commit to targets aligned with the Paris Agreement on climate change, including committing to net zero carbon emissions by 2050.

Retirement funds are known as superannuation funds in Australia. Two big funds QSuper and Sunsuper, which plan to merge and will have a combined A$200-billion under management, have faced pressure from environmental group the Australian Conservation Foundation (ACF). The group has asked its members to call for the funds to better account for their energy transition policies.

"The coal industry employs over 60 000 Australians and generates billions for the state and national economies and is forecast to continue doing so for decades to come,” Pitt said in a statement.

"Suggestions that two major superannuation funds, QSuper and Sunsuper, should abandon coal will deprive hundreds of thousands of members of a good investment option."

ACF said investors should exit thermal coal altogether by 2030.

“At the moment the priority is not investing in new coal, oil or gas ... investors need to be completely out of thermal coal by 2030,” an ACF spokesman told Reuters.

QSuper declined to comment while Sunsuper did not return a request for comment. Both funds are already members of the Climate Action 100+ Group of Investors.

The coal industry in New South Wales is currently proposing 23 new coal mines and mine extensions with a combined additional annual production of more than 155-million tonnes, a report by progressive think tank the Australia Institute found last week.

In a separate development on Tuesday, former prime minister Malcolm Turnbull was dropped from chairing a board that would oversee New South Wales' energy transition after he supported a moratorium on new coal mines in the Hunter Valley.