The future of a major open-cut gold mine in western NSW has been thrown into doubt after its owner said the project had been rendered unviable by a federal protection order.

ASX-listed Regis Resources said a decision by Environment Minister Tanya Plibersek to protect Indigenous heritage at the McPhillamys Gold Project, central-west NSW, would stop the mine going ahead.

The NSW Independent Planning Commission in March approved Regis’s application to mine gold in the area despite opposition from some in the local Aboriginal community.

Regis chief executive Jim Beyer said the company was ‘extremely surprised and disappointed’ that, after nearly four years of assessment, Ms Plibersek had decided to effectively block the development.

‘(This) declaration shatters any confidence that development proponents Australia-wide (both private and public) can have in project approval timelines and outcomes,’ he said in a statement.

The minister’s Indigenous-heritage protection declaration covers part of the Belubula River, which falls within the footprint for a proposed storage facility for cast-off material.

Regis has argued there are no other viable options for the facility and developing alternatives would require it to restart the lengthy assessments process.

‘This decision does impact a critical area of the project development site and means the project is not viable,’ it said.

The proposed area just outside of Orange, NSW, was to have an open pit, processing plant and tailings dam (pictured)

Ms Plibersek’s office did not immediately respond to a request for comment on the declaration over the mine, which is reportedly costed at $1 billion.

Under the Regis proposal, an 11-year open cut mining operation would be set up in the Blayney-Kings Plains district, near Bathurst.

The project would create almost 1,000 jobs in the region, the company said.

The Association of Mining and Exploration Companies, an industry lobby group, said the government order ‘lacks reason and commonsense’.

‘(It) sets a truly terrible precedent for investment risk in Australia,’ association chief executive Warren Pearce said in a statement.

Ms Plibersek had ignored the views of local traditional owners, the Orange Local Aboriginal Corporation, who did not oppose the project, he said.

‘They could see the value and future prosperity that this project could bring to their people,’ Mr Pearce said.

The Orange Local Aboriginal Corporation has also been contacted for comment.