The commission told the New Zealand Exchange today that it had completed a thorough review of trading in NZOG shares and had decided not to take the matter further. The review considered whether NZOG directors and other persons possibly in possession of non-public, price-sensitive information relating to the company may have traded in the period.

The review related to criticism that NZOG was slow informing the sharemarket about the Origin Energy-Genesis Power deal to develop the offshore Taranaki Kupe gas-condensate field.

Rumours that Origin was about to take over as operator of the field, through acquiring a 50% interest from Genesis, pushed NZOG shares up 13% in late January. Genesis and Origin announced their deal on February 5.

The commission review followed an NZX decision that said NZOG had not breached disclosure rules. It said negotiations need not be disclosed if still confidential or incomplete.

NZOG general manager Gordon Ward has already said criticism of his company relating to any Kupe transactions in which it was not directly involved was extremely unfair.

A number of other positive events that NZOG had direct involvement with, such as the imminent multi-well drilling program in offshore Taranaki licence PEP 38460 or recent access approval for an NZOG-led consortium to mine coal from the South Island's Pike River catchment, could also contribute to upward share price movements.