The receivers for Pike River Coal have begun marketing the mine in earnest.
PricewaterhouseCoopers says about 200 flyers have been sent to 30 companies that have already expressed an interest in the mine, to other companies that might be interested and to PricewaterhouseCoopers offices around the world.
One response has already been received and the company has signed a confidentiality agreement allowing it to investigate the finances of the mine and decide whether it wants to proceed.
PWC says that after indicative prices have been received, a shortlist will be chosen, and the sale finalised by August.
The Pike River coal mine has been closed since a series of explosions began on 19 November last year, when 29 men were killed. It is known to contain an estimated $6 billion worth of coal.