Government concessions to Maori on forestry could be worth up to $2 billion, according to the Kyoto Forest Association.
Papers leaked to Radio New Zealand News show iwi leaders are pushing for the right of first refusal to plant trees on Crown-owned land, as negotiations over the Emissions Trading Scheme continue.
They also want iwi to be the preferred joint venture partners in any forestry projects undertaken by State Owned Enterprises.
A deal is on the table which would allow Maori foresters to plant trees on conservation land that is deemed marginal, and to claim the carbon credits. This would form part of an agreement with the Maori Party to support the National Government's emission's scheme.
A key demand is flexible land use, which means that when trees are cut down there can be replanting in a different place. The iwi leaders also want Maori to have an effective right of first refusal over planting on Crown-owned land.
They want a fund set up to pay for tree planting, and the aquaculture sector to be included in free allocations of carbon credits. National and the Maori Party have indicated they are close to reaching a deal.
The Kyoto Forest Association says it understands the concerns of those foresters not included in the deal.
However, it says while the concession could run into the billions, it is not a huge amount in terms of the overall Emissions Trading Scheme.
Meanwhile, the Forest and Bird Protection Society of New Zealand says Maori could gain as much value from carbon credits by letting forests grow rather than by intensive planting.
Spokesperson Kevin Hackwell says managing the land against predators would allow a forest to grow at a much reduced investment.
Mr Hackwell says even with existing forests, additional carbon credits could be gained by the proper management of invasive pests.