Contact Energy, which generates about a quarter of New Zealand's electricity, said it expected to see little growth in future power demand and that the retail market would remain highly competitive.
The company's chairman Grant King, in speech notes to today's annual meeting, also said the Contact board would be considering how best to use the significant cash-flow of the business as its capital investment programme neared its end.
King said the company, which is just over half owed by Australia's Origin Energy, recognised about five years ago the importance of making Contact generation and fuel portfolio more flexible to respond to changes in the energy market.
"At that time we didn't foresee the impact the global financial crisis would have on global and regional economies, including here in New Zealand," he said.
"This has led to a material reduction in the demand outlook for energy in New Zealand," he said. "Nor could we anticipate a number of years of higher than normal rainfall which has created a surplus of energy in the New Zealand market," he said.