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.

Adani says it hadn't asked NAB for money to fund it's Carmichael coal mine development in Queensland's Galilee Basin. Credit:Peter Braig

"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.