NAB wasn't asked for mine funding - Adani

Indian business giant Adani has downplayed the significance of a major Australian bank announcing it won't finance its Queensland mine - because it hadn't asked for the money in the first place.

National Australia Bank on Thursday confirmed it had no plans to be involved in the financing arrangements for the $16 billion Carmichael coal mine development in Queensland's Galilee Basin.

"NAB looks at all financing project proposals on a case-by-case basis," a spokesperson said in a statement.

While the bank highlighted its internal policy to support a push toward a low carbon emissions economy, it didn't rule out supporting coal projects in the future.

"We again note that Adani has not sought funding from the NAB," an Adani spokesman said.

The Carmichael mine project, which includes rail, port and infrastructure development, will be the nation's largest if it goes ahead.

The project has attracted the ire of conservation groups, which argue it will increase carbon emissions, cause environmental degradation of the Great Barrier Reef through dredging and endanger native wildlife.

Conservationists now argue NAB's funding stance reflects the mine's "environmentally destructive" nature.

"The (government) should commit to not wasting taxpayer money on this doomed project," Greenpeace spokeswoman Nikola Casule said.

Greens Senator Larissa Waters agreed.

"We need investment in the clean energy industry, where the jobs will last, and a transition plan for coal workers, who are already losing their jobs because the coal price is in structural decline," she said.

Meanwhile, Korean giant LG is no longer a potential external customer for coal from the mine.

LG had signed a letter of intent to purchase four million tonnes of coal last year.

However, the non-binding arrangement became invalid as of July 2015.

Adani declined to comment on LG.

Commonwealth Bank of Australia ceased its role as a financial adviser for the project in August, after the Federal Court overturned federal government approval of the mine.