Trustpower has dropped its profit guidance on flat revenue growth, with below average generation volumes.
The Tauranga-based power generator expected the underlying profit for the year just ended in March to be in a range of $220 million and $226m.
The previous guidance was between $215m and $235m six months ago and down from last year's $267m.
It expected the current year's underlying profit to drop further to between $205m and $225m.
The company said fourth quarter long-run generation volumes were below average.
It said third quarter volumes were also down 26 percent on the year earlier, which had higher-than-usual volumes.