State owned coal company, Solid Energy, said it was reviewing all aspects of its business in response to low coal prices and the high value of the New Zealand dollar.
Solid Energy, which is on the Government's list for partial privatisation, said its medium-term outlook was similar to that faced by many other New Zealand exporters - lower commodities prices magnified by the continuing strong New Zealand dollar.
"The steep fall in demand and prices for internationally traded coal means the business anticipates its revenues will fall about $200 million in the current financial year," the company said in a statement.
International prices for high-grade coking coal have fallen over 40 per cent to below US$200 per tonne from well above US$300 per tonne in 2011 and are at their lowest point for some years.
Solid Energy said the outlook was different to that faced by the company during the 2008-09 global financial crisis.