Shares in Pike River Coal have fallen after the company almost halved its production forecast.
The listed coal miner recently commissioned a hydro-mining system at its underground mine near Greymouth, which uses high pressure water to cut large quantities of coal.
Earlier this year it expected to produce 620,000 tonnes of coal in the year to the end of June, but now expects to produce between 320,000 and 360,00 tonnes.
The company's new chief executive, Peter Whittall, says the new forecast is a result of slower-than-expected progress in developing underground roadways and delays caused by machinery upgrades.
The company says it will make an announcement next month about its funding requirements and repayment of a loan from New Zealand Oil and Gas.
Shares in Pike River fell 3 cents to $1.06 at close of trading on Tuesday.