Tahmoor Coal, a subsidiary of SIMEC Mining, sought approval from NSW's Independent Planning Commission to establish 12 new longwall panels to the south of the mine.

SIMEC Mining is owned by Mr Gupta's GFG Alliance.

This would enable miners to extract an additional 33 million tonnes of mostly coking coal over the next 10 years, which will mostly be exported.

The IPC on Friday said in a statement it had granted development consent for the extension, with environmental and social conditions attached.

The commission said the submissions in favour of the project - such as its economic benefits to the community - outweighed any potential concerns arising due to water, air, biodiversity or cultural factors.

However, the commission said Tahmoor Coal would be obliged to limit greenhouse gas emissions where possible, appropriately compensate affected residents and shorten two proposed longwall panels.

In total, the IPC imposed 168 development conditions on the extension.

"The commission agrees with the department's findings ... that the proposed extension of the existing Tahmoor coal mine is strategically justified and is in the public interest, and that the identified impacts can be appropriately managed through the conditions of consent imposed," the IPC said.

Thousands of jobs associated with Mr Gupta's Australian operations are currently on the line after Citibank, acting on behalf of Credit Suisse, launched court action to wind up OneSteel Manufacturing and Tahmoor Coal.

The action came after the collapse of Mr Gupta's major lender Greensill Capital, which filed for administration in early March.

GFG Alliance has vowed to vigorously defend the court action, saying it does not conduct any financing with Credit Suisse.

Australian Associated Press