Oct 16 (Reuters) - Australian coal miner New Hope Corp said on Friday it will lay off up to 75% of its workforce at the corporate headquarters due to uncertainty around approvals for its enviromentally-contentious New Acland mine.

New Hope has already laid off 175 employees at the mine and is still is awaiting approvals for mining lease applications for stage 3 of the Queensland project, following a legal victory last year over an activist group that sought to halt the expansion.

"We have had to make some extremely difficult decisions but, in reality, even if we were granted approvals for Stage 3 today, we are in for a tough couple of years as we ramp up again," Chief Executive Officer Reinhold Schmidt said in the Friday's announcement.

Under the restructuring, the majority of executive positions at the Brookwater, Queensland office will be made redundant by the end of November, the company added. It did not specify how many positions would be lost.

Already reeling from posting an annual loss last month due to sharp drop in coal prices and demand, there is now added pressure on New Hope after reports that China was planning to impose a ban on coal exports from Australia. (Reporting by Anushka Trivedi in Bengaluru; Editing by Sam Holmes)