The slump in world oil prices has led to a large loss for New Zealand's biggest oil and gas explorer.
NZ Oil and Gas (NZOG) reported a $27.6 million loss in the six months ended December compared with $7.7m a year ago.
The company's revenue increased 21 percent to $65.4m, as income from its Cue Energy investment offset falls from its stakes in the Tui and Maari oilfields.
NZOG said it was writing down the value of the two fields because of the fall in world oil prices, which have more than halved over the past year.
With oil prices in the low $US30 a barrel range it expected the Tui field would become uneconomic in the next two years and will probably be abandoned in early 2018.
NZOG said it was not spending on exploration beyond contractual obligations. It was also not replacing a retiring director, and the board would take a fee cut.
"The board intends to manage capital carefully and retain only capital needed for the company's strategy," NZOG chairman Rodger Finlay said.
It would also change its accounting methods, and would treat exploration costs as expenses when they were incurred. They had previously treated them as an expense when a project was abandoned, the company said.
NZOG did not declare an interim dividend.