Power company Contact Energy has frozen its prices for residential electricity in parts of Wellington, Hawke's Bay, the East Coast and Christchurch.
Spokesperson Jonathan Hill says the freeze remain in place until October 2010.
Mr Hill says the Contact Energy will cover the cost of any increases in charges to it from the national grid and lines companies in that time.
He says the move enables Contact to keep prices competitive for existing customers, as well as enticing new ones.
Mr Hill says the price hold is not a result of a recommendation Energy Minister Gerry Brownlee for companies to refrain from putting prices up.
Mercury Energy has no immediate plans to follow the price freeze.
Spokesperson James Munro says its service is already cheaper than electricity prices supplied by Contact.
Mr Munro says after its pricing review in April, only customers in Auckland's North Shore received a slight electricity price rise this year.