The Waitangi Tribunal says the Trans-Pacific Partnership does not breach the Crown's treaty obligations.
In a ruling released yesterday, the tribunal said that the treaty clause in the 12-country agreement should "provide a reasonable degree of protection to Maori interests".
It said that the inclusion of a treaty clause in the Trans-Pacific Partnership (TPP) was "to the credit of successive New Zealand governments".
However, the tribunal expressed concerns about the right of foreign investors to bring claims against the New Zealand Government, saying it "may have a chilling effect" on the Crown's ability to meet its treaty obligations.
The tribunal said this should be the subject of further dialogue between the Crown and iwi.
The TPP includes a specific clause which allows the Crown to take "measures it deems necessary to accord more favourable treatment of Maori, including in fulfilment of the Treaty of Waitangi".
In urgent hearings held in March, the tribunal heard from claimants who said that the clause would not protect their treaty rights, and that the TPP gave too much power to foreign investors.
Professor Jane Kelsey, who was one of the claimant's experts, said the tribunal's report was not a victory for the Government.
The substance of the tribunal's report vindicated claimants' concerns, she said, in particular with regard to foreign investors' special rights.
In the end, the tribunal's finding was a pragmatic one, she said, because it could not force Government to reopen negotiations on the trade deal.
Trade Minister Todd McClay welcomed the tribunal's report.
He said New Zealand's approach to free trade agreements reflected the constitutional importance of the treaty to New Zealand.
The specific recognition of the treaty in the TPP meant nothing would prevent the Crown from meeting its obligations to Maori, he said.
During the hearings, the Crown's experts had argued that the treaty protections had been honed and consulted on for more than decade, since a clause was first included in a fair trade deal with Singapore in 2001.
The tribunal was critical of the Crown's consultation on the TPP before the text of the agreement, but said it had not made any findings in this area.
Since the TPP text was finalised and signed off in March, the Government has carried out a nationwide roadshow and select committee hearings on the TPP.
But claimants argued that there should have been more consultation before negotiations were completed.
The Foreign Affairs, Defence and Trade committee tabled its report on the TPP on Wednesday.