Contact Energy is increasing the cost of gas for its Auckland customers.
The company says an average household on its "Living Smart" plan will pay nearly $64 more a year, a 9 per cent increase.
Contact's general manager trading, Steve Cross, said the price rise was due toa "significant upwards trend" in the wholesale gas price and rising transmission costs.
"Contact has to strike a balance between managing the impact of all these increases, and remaining a viable, competitive energy provider in Auckland," he said.
"That is why the company is announcing increased gas prices today."
The price rises will start on January 15 and apply to both domestic and business customers.
Contact has announced after-tax profits of $118.3 million for the past year, up nearly 10 per cent from the year before.
Its 51 per cent owner, American energy giant Edison Mission, is looking at selling its overseas assets, which may prompt a takeover offer for Contact.
The gas price rise comes less than a month after Contact's state-owned rival Genesis Energy raised gas prices for its 97,000 domestic customers by 12.7 per cent - the equivalent of a $71 increase on an annual bill.
It is only eight months since Genesis last lifted its gas prices, with increases of up to 15 per cent.
The cost of all forms of energy - gas and electricity - is expected to jump dramatically in the next few years, due mainly to a drop in natural gas available from the Maui field.
This cheap gas is used to generate electricity in power stations, as well as being burned in homes and factories.a
