The decision gives the Government the green light to proceed with its flagship "mixed ownership model" policy under which it hopes to raise $5 to $7 billion by selling up to 49 per cent of Mighty River, Meridian Energy, Air NZ and possibly Solid Energy.
It plans to sell shares in Mighty River in the second quarter of this year.
The appeal was brought by the Maori Council and the Waikato River and Dams Claims Trust after their High Court bid to block the sale of Mighty River was dismissed late last year.
In the Supreme Court hearing late last month and early this month they challenged the High Court's Justice Ronald Young's ruling that the sale of shares was not reviewable by the courts for consistency with the principles of the Treaty.
In a unanimous decision, the Supreme Court ruled in favour of the council on this point but not on the issue of whether the sale of shares would affect the Government's ability to make subsequent redress for any claims over water and geothermal resources.
Lawyers for the Crown had hoped the decision would be delivered last Monday to allow the partial sale of Mighty River to go ahead according to the Government's "preferred timetable''.
However the court informed the Maori Council and Crown lawyers it could not meet that timeframe.
The delay in delivering the decision has fuelled speculation the five judges hearing the case had differing views.
The Supreme Court also found against the council on their argument that the Government had failed to meet requirements under 2010 Waikato River settlement legislation requiring it to consult with Waikato River iwi over the disposal of rights over the river.
Finance Minister Bill English and State Owned Enterprises Minister Tony Ryall said Cabinet would next Monday consider a timetable and other details of the Mighty River offer, "including how New Zealanders will be at the front of the queue for shares".
"We expect to be in a position to confirm those details soon afterwards.
"We are pleased to be getting on with what we were elected to do."
Ryall said the Government "has always been firmly of the view that the partial sale of shares does not in any way affect the Crown's ability to recognise rights and interests in water, or to provide redress for genuine Treaty claims."
English, in a speech delivered this afternoon, reiterated his commitment to the programme of power company floats.
The float would be a "shot in the arm" for capital markets and was expected to remain 80-90 per cent owned by New Zealanders, English said in a lunchtime speech to the Auckland Chamber of Commerce today.
"New Zealanders will be at the front of the queue for shares," he said. "Including the Government's majority stakes, ministers expect 85 per cent to 90 per cent of the shares across the programme to be held by New Zealanders, after the IPOs."
English said New Zealand needed to become a magnet for investment. Although he conceded there was no "silver bullet" to make that happen the Government had to be doing "hundreds of small things well" to get the business environment right.
Yesterday, English said information from the Mighty River Power float could lead to a revision of the overall estimates of proceeds from the Government's SOE sales programme.
"It's possible the numbers will move around."
A $5-$7 billion figure was the estimate given in the May 2011 Budget for the sale proceeds of up to 49 per cent of four state-owned enterprises (Mighty River Power, Genesis, Meridian, Solid Energy) and Air New Zealand.
- with BusinessDesk
