BHP has submitted an application to continue operating its Mt Arthur open cut coal mine near Muswellbrook until 2030, at which time it will close.
The company announced last year that it was bringing forward the mine's closure from 2045 to 2030 after it failed to find a buyer for the project.
The current consent expires in June 2026 and will need to be extended for a further four years to bridge the gap.
BHP NSW Energy Coal Vice President, Adam Lancey said feedback from the local community, surrounding mines and other key stakeholders informed the modification report, which had recently been submitted to the Department of Planning and Environment.
"This is a major milestone on our pathway to 2030 and will ensure we have the time to implement equitable closure plans," he said.
"The additional four years we are seeking to operate provides us and the community more time to work together to transition Mt Arthur Coal to closure."
The report will soon be placed on public exhibition, which will allow workforce, suppliers and the community an opportunity to comment on the plan.
It is expected that the modification will be determined in 2025.
BHP recently revealed that hiking and mountain biking trails situated alongside renewable energy projects and grazing cattle were among the post mining land uses under consideration for the 7000 hectare site.
Mr Lancey said the seven-year timeframe leading up to the closure provided the opportunity to consult, prepare, plan and make thoroughly considered, long-term decisions for the future of the mine's 2000 employees and surrounding communities.
The company's vision for the closure and rehabilitation process is based on "people, planet and prosperity".
"Our aspiration is to deliver sustainable landforms and land uses which can provide a positive legacy for generations to come post Mt Arthur Coal's closure," Mr Lancey said.
BHP estimates that about 35 per cent of Mt Arthur's workforce will be at retirement age in 2030.
It is estimated that it will take between 10 and 15 years to fully rehabilitate the mine site.
Employees, local suppliers and businesses, Indigenous groups, governments and community leaders will be among the groups consulted on the process.
The site is strategically located with established connections to rail plus an array of existing high-quality infrastructure, including potential access to a high capacity electrical network.
The closure of Mt Arthur will also mark the end of BHP's association with the Hunter, which began with the opening of the Newcastle Steelworks in 1915.
