TrustPower, the Tauranga-based electricity generator, says a slight dip in customer churn is likely to be linked to high wholesale prices.

The NZX-listed company, majority owned by Infratil, has seen its customer base shrink over the last year as consumer switching between retailers surged. It has refused to compete at what it claims is uneconomic pricing.

However, customer churn has dropped, with 11,000 fewer switches in June than a year ago, the height of the "Whatsmynumber?" campaign.

In the three months to June 30, TrustPower's electricity customers fell by 1000 to 208,000, compared to a drop of 11,000 over the previous nine months.

Chief executive Vince Hawksworth said several retailers had announced that they would tone down customer acquisition, as low South Island lake levels caused wholesale prices to rise.

"Wholesale prices went very high and so I imagine people who were selling at a loss stopped selling at a loss for a while," he said.

Recent high prices were caused by low lake levels rather than generation shortage, Hawksworth said.

TrustPower was unlikely to confirm construction of any major projects in New Zealand in the near future.

"There's still a bit of structural oversupply, so until there's a bit of a removal of capacity or load growth goes up a bit, those [New Zealand] projects will be on a slower track than our Australian ones."

Last week the company confirmed it was proceeding with construction of Snowtown 2, a 270 megawatt extension of its existing South Australian wind farm north of Adelaide.

The scale of the project meant it was unlikely that TrustPower would make any major announcements about its next Australian project in the next 12 months.

- © Fairfax NZ News