“Based on what we currently know, we consider the Pohokura authorisation was granted on the basis of information that was false or misleading, or that there have been material changes in the circumstances since the authorisation was granted,” said commission chair Paula Rebstock yesterday afternoon.

“The material change is that the nexus between joint marketing and sale and early production no longer exists. Without that, the public benefit analysis alters substantially in a way which was discussed by the commission when it gave the authorisation. The commission indicated in its authorisation decision that without that nexus, the authorisation would not have been given.”

The partners had told the commission that a joint approach was necessary to ensure early production from the Pohokura field and that possible multi-million-dollar delays could result if separate marketing and selling conditions were imposed.

The commission later accepted that the substantial benefits from joint marketing and early development of the field, estimated at between $NZ47.8 million and $NZ81.9 million, outweighed the previously described “large overall detriment”.

However, the partners later turned around and announced separate marketing would not delay the June 2006 development deadline the commission insisted on.

If the commission decides to revoke authorisation for joint marketing-selling, it will only be the second time it has had to revoke an authorisation of anti-competitive behaviour.

The partners are Shell NZ (operator), Todd Petroleum and OMV.