Australia's Labor government led by Prime Minister Anthony Albanese in December passed legislation to cap natural gas prices for one year, and secured agreements from the coal producing states of New South Wales (NSW) and Queensland to cap the price of coal sold to power plants.

New South Wales Treasurer Matt Kean said on Thursday the state would require those coal miners that do not currently sell into the domestic market to reserve between 7% and 10% of their output for domestic use.

Thai firm Banpu's Centennial Coal and Peabody Corp are the main suppliers of coal to power plants in the state.

Other major coal miners in the state include BHP Group, Glencore Plc, Whitehaven Coal, Yancoal and New Hope Corp, which concentrate on exports.

The new arrangement would ensure a fairer sharing of the burden among coal companies as part of the federal government's drive to put downward pressure on energy prices, Kean said.

"I know those currently providing coal for the local market will appreciate that companies enjoying super profits on the back of the war in Ukraine will now do their part for the domestic market," he said. "Of course they should provide Australian production for Australian consumers."

Whitehaven said on Thursday it was in talks with state government officials to supply coal.

(Reporting by Melanie Burton and Sonali Paul in Melbourne; Editing by Jamie Freed)