The Government and Ngai Tahu have confirmed a Treaty top-up clause is set to become active.
Both Ngai Tahu and Waikato-Tainui negotiated "insurance clauses" as part of their original settlements, entitling each iwi to a percentage of all future Treaty settlements once they exceed $1 billion in 1994 dollar terms.
The Government has acknowledged that amount could be reached this year, which would entitle Ngai Tahu to 16.1 per cent and Waikato-Tainui to 17 per cent of all future Treaty settlements.
The settlements were last calculated at $787 million in 2008-09.
Te Runanga o Ngai Tahu kaiwhakahaere Mark Solomon said: "Our expectation is that the mechanism will possibly be triggered this year, or next year at the latest."
To date, 26 settlements have been completed, including Waikato/Tainui ($170 million) in 1995, Ngati Awa ($42.39 million) in 2003 and Ngati Ruanui ($41 million) in 2001. Forty-three groups are working towards settlements.