The new Mighty River valuation means the Government could raise about $2 billion of the $5 billion-$7 billion it hopes to raise from the entire asset sales programme with one transaction.
The biggest company earmarked for sale, Meridian Energy, which generates about 30 per cent of New Zealand's electricity, gained $79 million in value, giving a total value of $6.58 billion.
Genesis, however, lost $70 million in value, taking its total worth to $2.05 billion.
The Government has put the sales of Solid Energy and Air New Zealand on the backburner due to recent operating uncertainties for both.
A board valuation for Solid Energy was not given.
"Changing and challenging sector conditions and a large turnover in board members including a new chair" meant a new valuation had yet to be completed, Comu said.
The company's value was slashed by about half a billion dollars to $2.77 billion last year as coal prices softened.
Air New Zealand's value was determined by changes in price for the 24 per cent of its shares already traded on the sharemarket.
It lost $213 million in market capitalisation, taking its theoretical market value to $690 million.