Vector had wanted to buy essentially all of AGL’s cornerstone shareholding in NGC by acquiring AGL’s New Zealand holding company (AGL NZ Ltd which 64.2% of NGC). However, it required an exemption from rules that shareholders must sell directly to the company making the offer; and the panel earlier this week ruled against that.

Media reports here quote AGL media relations manager Jane Counsel as saying the exemption had been sought because it would allow a "cleaner and quicker" exit from New Zealand.

However, alternative structures had the same tax implications and would not materially change transaction costs.

"The alternative structure will reflect a sale share price of NZ$3 a share and is not expected to materially change the net sale proceeds of A$760 million or the anticipated completion as previously announced to the market," AGL told the ASX yesterday.

Vector is also still waiting for approvals from the Commerce Commission under competition rules and electricity industry regulations.

Origin Energy was successful less than two months ago in getting a dispensation from the panel to buy Edison Mission Energy's holding company in New Zealand, rather than all its shares in Contact Energy, and commentators say AGL may have been unlucky in having its application heard just weeks after the panel’s decision to grant a waiver in the Prime-Powerco takeover.