Mighty River Power and Meridian Energy will keep the price they charge for electricity on hold this year for the third year in a row.
Both companies say they will pass on network costs that could account for close to half of a bill.
Meridian said network costs would increase in some regions but could fall in others.
"A large portion of customer bills covers the delivery of electricity across the national grid and distribution networks. These costs are regulated by the Commerce Commission and are charged to electricity retailers."
All power companies are locked in a tough fight for retail customers.
Mighty River Power customer general manager James Munro said regulated charges relating to lines companies and national grid operator Transpower would be passed on as usual.
"For the third year in a row we have decided not to increase our headline energy prices. That fact reflects both our customer first approach and the intensely competitive retail electricity market where we have more players competing for customers than just about any other retail sector."
A Trustpower spokesman said it would review pricing on a regional basis staged through the year and expected to pass through Transpower, network company and Electricity Authority charges.
"Energy and retail components will reflect the highly competitive market and we will assess this on a regional basis when we review prices."
Genesis said it reviewed its electricity and gas prices "regularly".
Contact Energy said it had not put up prices for two years and said last year that it could not see a price rise in the "foreseeable future".
Meanwhile the Wellington-based company announced it had signed a new deal with Maui Development Ltd to purchase between 22 and 26 petajoules of gas over a two-to-three- year period that significantly boosts its overall forward supply.
The cost of the deal has not been disclosed and it replaces an agreement with Maui that expired at the end of last year. Contact generates about a quarter of New Zealand's electricity, has 22 per cent of the electricity retail market, and is one of the largest wholesalers and retailers of natural gas.
Contact's chief generation and development officer, James Kilty, said the new Maui agreement, together with existing contract gas and reserves at its Ahuroa Gas Storage facility, gave the power company more flexibility to use less gas than in previous years when running its thermal power stations, and to tailor the volume of use based on its needs.
Contact has 12 power stations nationwide with its thermal stations including the combined cycle Otahuhu B and Taranaki, and Te Rapa co-generation.
Late last year Contact reached agreement with Genesis Energy to buy 27 petajoules of gas from its portfolio of gas contracts from January 1, 2015, through until December 31, 2020, and it has also announced a deal for three petajoules of swap gas.
It has been running down the amount of forward contracted gas volumes it has until now saying in its annual results last August that its gas storage allowed it to have a patient approach to contracting new gas.
At that point it said it had 43 petajoules of contracted gas volumes in 2013, 29 petajoules in 2014 and only eight petajoules for 2015 and five petajoules for 2016.
Contact also lifted the price of gas last month by an average of between $11 and $49 a year because of changing distribution and transmission costs it said were out of its control.
- Additional reporting BusinessDesk