Last week EnergyReview.Net revealed that Santos had already obtained board approval to try for Kupe, with some Santos staff visiting New Zealand about six weeks ago to discuss the south Taranaki field with present operator Genesis Power and associated parties, such as Crown Minerals.

ERN now understands that Brisbane-based Origin Energy - a long-time explorer in New Zealand, with interests in several onshore and near-shore Taranaki permits plus an East Coast and Canterbury licence - has also visited the Genesis data room in Auckland as part of its due diligence process.

Late last year OMV Petroleum's Australian then-boss Wolfgang Zimmer told ERN his company was definitely interested in becoming Kupe operator. However, it is now believed OMV's enthusiasm for Kupe has waned, with it taking over Preussag Energie and concentrating on the development of the Pohokura gas-condensate and Maari oil fields off Taranaki.

An American candidate could be Newfield, which operates the Challis and Jabiru offshore fields in the Timor Sea and is known to have previously expressed an interest in New Zealand.

Apache, which has long been interested in crossing the Tasman and getting involved in this country's small but vibrant energy industry, is believed to be a fourth Kupe candidate.

Genesis chief executive Murray Jackson has declined to identify the six international companies, which last month submitted Request for Qualifications to his company, nor the people who have since visited the Greenlane data room. However, he recently told ERN he was very pleased with the level of interest in Kupe and the companies' desire to complete due diligence in time to enable Genesis to appoint an operator by October 1.

Genesis wants the successful bidder to take a probable 40% stake in Kupe, as well as taking over as operator, with a view to having the marginal 1986 discovery developed by 2006-07.