“The review is ongoing and will be completed in conjunction with the audit of the company’s annual financial statements due for completion on or about 26 September 2014,” Guildford said.

“While no final decision has been made, the board believes it is likely that a non‐cash impairment charge for the non‐current Australian assets in the range of $40 to $50 million (pre‐tax) will result.”

Guildford, which is primarily focused on its early phase Mongolian coking coal mining operations, expected no “cash flow consequences and no effect on any covenants in the company’s debt facilities” from such a write-off.

In August Guildford agreed to sell its Queensland portfolio of projects to Singapore-listed Sino Construction for $US25 million ($A28 million) – up $2.5 million from the first offer – plus agreements for royalties and management fees.