Mighty River price fall fear

Contact shares closed at $5.38 last night compared with $5.72 the night before Labour and the Greens announced their policy. Photo / Mark Mitchell

Treasury says impact of Labour-Greens policy likely to mirror Contact's 6pc plunge.

The controversial Labour-Greens electricity market policy which has knocked 6 per cent off the value of Contact Energy has probably reduced the price the Government will get for Mighty River Power by a similar amount, Treasury says.

The Mighty River initial public offer enters its final phases tomorrow with the book build process by which institutional investors such as pension and Kiwisaver funds bid for shares and thereby help set the final price ahead of its listing on Friday.

The offer of up to 49 per cent of the Waikato River-based generator and retailer has an indicative price range of $2.35 to $2.80 a share, which values the shares being sold in the company at $1.61 billion to $1.92 billion.

Treasury deputy secretary John Crawford, in charge of the partial sales process for Mighty River Power, Meridian Energy and Genesis Power under the Government's "mixed ownership model", yesterday acknowledged the Labour-Greens policy would have an effect on price.

Labour says the policy to establish a new single buyer of wholesale electricity at prices that reflect generation costs and a "fair return on capital" would have a $700 million a year impact on power company profits.

"Certainly sophisticated investors have taken that into account and are giving us their view of price," Crawford said. "Inevitably, markets are efficient, people make judgments about both the desirability of the stock and the price of the stock based on all the information that comes out. If new information comes out they generally reassess that now. Now we have seen the impact of that on the market which has been the impact on Contact and that's probably as good a proxy as you'll get for the proxy on price."

Crawford said the impact of the policy proposal on Contact's share price was less than 10 per cent, but he acknowledged that possible impact on the value of Mighty River was "a big number itself".

Contact shares closed at $5.38 last night compared with $5.72 the night before Labour and the Greens announced their policy.

That equates to a $249 million or 5.9 per cent drop in market cap.

If the Labour-Greens policy had the same impact on the Mighty River shares being sold it would take $95 million to $113 million off their value.

Prime Minister John Key yesterday said the Government would not release information about the level of demand from retail investors until the bookbuild process was complete because of securities law requirements and the need to maintain bidding tension.

He said they were pleased with the level of engagement.

Using information accumulated during the bookbuild, Government ministers will set the final price for Mighty River shares and announce it as early as late tomorrow. The shares will be listed and may be traded on a "conditional" basis on Friday.