In a report finally made public yesterday, the Wellington-based tribunal said the government was entitled to nationalise petroleum resources in 1937, but that its failure to compensate land owners for the loss of property rights or pay them royalties was a breach of the Treaty of Waitangi.

Todd Energy's reaction is somewhat more circumspect than that of the PEANZ organisation, which yesterday said it was relatively unconcerned by the report.

The report - on a claim by Taranaki's Nga Hapu o Nga Ruahine clan that oil and gas are taonga (treasures) - also said the government should negotiate a royalties deal with affected Maori and not conclude the sale of its 11% interest in the undeveloped Kupe field until the matter had been settled.

That prompted United Future leader Peter Dunne to accuse the tribunal of extremism, and New Zealand First leader Winston Peters to say European land owners had also been affected by the 1937 Petroleum Act.

Todd Energy chief executive Richard Tweedie told Energyreview.Net that the tribunal and its recommendations had the potential to be a "significant turn off for exploration at the very time New Zealand needs more exploration".

The tribunal's report and, to a lesser extent, the Commerce Commission's draft on Pohokura gas marketing, could be seen as negative signals for overseas explorers contemplating coming to New Zealand, said Tweedie.

Last week the commission gave its draft approval to the Pohokura partners - Shell New Zealand, Todd Energy and OMV - to jointly market and sell Pohokura gas, but only for the first five years of production and subject to a number of conditions.

"Many of the world's majors are in Australia, why are they not here?" Tweedie asked. "They are not here because they are not sufficiently interested."

While New Zealand's fiscal terms might be attractive for explorers, overall prospectivity was not great, with the Taranaki Basin being the best.

The government needed to tip the balance in favour of such companies as Apache coming here, but indigenous claims to oil and gas resources or royalties might mean the continued deferral of that much needed increased exploration effort to find replacements for the faltering Maui field, Tweedie added.

Prime Minister Helen Clark has already rejected suggestions that this country's petroleum resources are up for negotiation, saying the national interest over-rode the Treaty of Waitangi; while Treaty Negotiations Minister Margaret Wilson has rejected suggestions that there is nothing stopping the government giving compensation for royalties.