The facts behind Vector

Vector is a monopoly power lines company, created when the lines side of Mercury's business was split from the generating and retail side. Before the creation of Mercury, the Auckland Electric Power Board covered both sides.

* The Auckland Electricity Consumer Trust owns all the shares in Vector.

* It is the largest publicly owned community trust in New Zealand.

* Five trustees are elected to the trust every three years. The trust receives an annual dividend which it gives to 285,000 customers in Auckland City, Manukau and part of Papakura, through a credit on power bills.

* Vector describes itself as an "energy network company" but it also owns a fibre optic communications network in Auckland and Wellington.

* It operates under two brands: Vector for Auckland City, Manukau City and most of Papakura; and UnitedNetworks in Wellington and in north and west Auckland.

* It owns the gas pipelines across Auckland. It has 27,700km of cables, with 54.3 per cent of them underground. It owns 158,500 poles. It owns 5000km of gas pipeline with 75,000 consumer connections.

* Vector has grown dramatically in the past few years, with its 2002 purchase of the neighbouring lines company UnitedNetworks taking it to the top of the ladder of New Zealand's biggest energy network companies.

* It has more than 651,000 electricity connections - a 35 per cent share of New Zealand's electricity distribution sector.

* Almost 94 per cent of these consumers are in Auckland and Wellington.

* It is allowed to generate its own electricity, but is not allowed to be an electricity retailer.

* Vector cannot charge whatever prices it wants to. With the other energy network companies, it is covered by the Commerce Commission under a system of "threshold" regulations.

* The commission assigns a rating to each company, and allows each to raise prices accordingly.