The mine employs approximately 500 people and the company had outlined a review on 25 September 2012 with the process expected to last about 3 months.
Hargreaves said in a statement, "Initiating this process is considered to be prudent business practice and does not indicate that a decision on the future of Maltby has been taken."
The company’s coal mine in South Yorkshire also faces closure due to unfavourable geological conditions.
According to company reports coal mining delays may reduce revenues by £12m for the year ending 31 May 2013.
The company’s board is expected to arrive at a decision in October 2012 after reviewing reports of geological, financial and health and safety risks of the mine.
