Rio Tinto Coal Australia subsidiary Coal & Allied has failed to overturn a court decision preventing the expansion of its Mount Thorley Warkworth (MTW) mine in New South Wales (NSW).
MTW is an integrated operation of two adjacent open cut mines that are 15km south-west of Singleton in the Hunter Valley region of NSW.
The Wall Street Journal reported that the mine's expansion has been in limbo since the NSW Land and Environment Court ruled in 2013 that it would threaten endangered ecological areas and adversely affect residents of the nearby town of Bulga.
The case was then taken to the NSW Court of Appeal, which refused to overturn the decision.
Rio Tinto has unveiled a revised expansion plan, following the latest court ruling.
The company has agreed to offer 1,800ha of land for a national park, A$4m ($3.7m) towards a regeneration programme for Warkworth Sands Woodland and money for training local youth.
Coal & Allied managing director Chris Salisbury said the court's decision comes as no surprise, given the limited scope of the appeal available to the company.
"We remain committed to securing new approvals that will provide a long-term future for Mount Thorley Warkworth mine and the jobs of its 1,300 workers," Salisbury said.
"Our current approvals will only allow Mount Thorley Warkworth to maintain existing production and employment levels until the end of 2015. It is essential we secure longer-term approvals before then, to ensure the mine remains economically viable."
Salisbury noted that the new proposals the company is putting forward include a range of upfront measures that go above and beyond the existing comprehensive programme to manage impacts from Mount Thorley Warkworth mine.