Competitive markets don't need regulation. Needlessly over-regulated markets harm the economy and can constrain growth, writes David Parker.

The Grey Power-led petition to force a referendum on the Government’s partial asset sales policy has failed because it did not have enough signatures.

Z Energy's second full year of operation since its sale to local investors by Shell has produced a 13.1 per cent lift in operating earnings, although sales have fallen.

New Zealand's leading business lobby groups say the Labour Party and the Greens have "ambushed" businesses with their controversial electricity policy which they claim sets a "disturbing precedent" for further intervention.

Labour and the Greens have defended their controversial electricity policy after New Zealand's business leaders issued an open letter asking them to withdraw it.

A broking firm says a 10 per cent reduction in power prices could be achieved in the current electricity market - meaning the Labour-Greens proposal is unnecessary.

A protest which halted a mining giant's oil exploration on NZ's high seas and prompted a controversial law change cost taxpayers nearly $1.7 million, documents show.

The war of words over the Opposition's electricity market reform plan has flared again as political opponents traded fire over the plan's economic impact.

Mighty River Power expects it would take at least five years for the Labour and Green party's new electricity policies to be enacted, and John Key says it won't happen.

Labour's proposed shake-up of the energy sector could slash up to 20 per cent off the value of Mighty River Power although analysts rate the chances of the Opposition's plan going ahead at less than 50 per cent.

Political commentators have been quick to point out that New Zealand voters now have a real choice, writes Liam Dann. Sometimes it seems we have two poor choices.

Matt McCarten looks at the plans of Labour and the Greens to set up an electricity agency, NZ Power, if they are elected next year.

The Labour-Green proposal to cut Kiwi householders' power prices through radical market reform has been given the thumbs-up by consumer groups, but energy sector commentators are divided on the plan.

Labour and Greens want Crown-owned single buyer to set electricity prices for generators.

The Government says Labour and the Greens are trying to sink the Mighty River Power share float with a hastily drafted threat to impose Soviet-style intervention on the electricity market.

Labour and the Greens are promising a major intervention in the retail power system in a bid to lower residential power prices if they win next year's election.

Petrol prices are heading down towards the $2 mark with BP announcing a 3c price cut today as international oil prices tumble.

Brokers and analysts are predicting a strong take-up of Mighty River Power shares as the offer opens to the public today.

Crucial face-to-face talks between the owners of the Tiwai Point aluminium smelter and Meridian Energy resume in Wellington today, and could take the rest of the week.

The Government has set a price range of $2.35 to $2.80 per share for the partial privatisation of Mighty River Power.