Largest wholesaler and retailer of gas in New Zealand; generates about 30% of the country's electricity; is also a retail supplier of electricity; has 10 power stations around the country including hydro, geothermal and gas turbine

One of New Zealand's biggest electricity distribution companies, formerly known as Dunedin Electricity; caters mainly to the Otago region

Company engaged in the generation and retail distribution of electricity; owns seven power generating plants in the North Island, and distributes gas and electricity in many locations across New Zealand

Company that works with industries and governments to establish and operate trading exchanges for commodities and services such as electricity, ga and telecomunications; part of the FirstRand Group

Retail arm of Mighty River Power, an electricity generator; sells electricity to 250,000 homes and businesses throughout the upper North Island; also offers a combined electricity and gas package in some areas

State-owned company; largest generator of electricity in New Zealand; also sells electricity to residential, industrial and commercial customers; has hydro power stations at Tekapo, Ohau, Benmore, Aviemore, Waitaki and Manapouri

Auckland City's water and wastewater utility company, 100% owned by Auckland City Council;

State-owned electricity generator and retailer; produces mainly from its nine hydro power stations on the Waikato river but also from geothermal fields and methane gas from landfills and natural gas

Lines company engaged in the conveyance of electricity in Whangarei and Kaipara districts in Northland region; also owns and operates a 3 MW hydroelectric power station near Titoki; contracting division competes for work throughout New Zealand

Nationwide supplier of piped (mains) natural gas and bottled gas (LPG) to homes and businesses; OnGas is the retail gas brand for Vector Limited, a multinetwork infrastructure company