The Electricity Commission has turned down a proposed upgrade to the transmission grid from Auckland to Albany for the time being.
Transpower's $480 million project would have seen a cross harbour cable between Penrose and Albany.
The second part of the plan relating to a new 220 kilovolt cable between Pakuranga and Penrose will proceed.
The commission says uncertainty about whether a Genesis Energy plant at Rodney will proceed makes it an inappropriate time to approve Transpower's proposal.
And it pointed out the cable won't be needed until 2016 and will take only four years to build.