A possible dip in power bills for many North Islanders

Lines companies Powerco and Wellington Electricity have had downward adjustments made to their allowable revenues.

The changes are being made to ensure all regulated lines companies have the same weighted costs.

Powerco's allowable revenue from customers in the central north island will drop by about 150 million dollars, while Wellington Electricity's will go down by 18 million.

The Commerce Commission says this should mean lines charges should drop in people's power bills - provided retailers pass on the savings.