Deal merges the largest suppliers of metering services on the North Island's reticulated natural gas distribution network.

There is "no perfect model" for electricity systems and other countries use similar methods to set prices and to procure investment.

The gas distribution network owner has enough of a cushion to ensure its credit rating doesn't need to be cut.

Commerce Commission has confirms the gas distribution network owner will make cuts. 

"This result demonstrates how we have continued to grow, in spite of the new economic environment."

The Commerce Commission has evaluated the 2008-11 performance of all 29 electricity distributors.