Whanganui Iwi kaumatua John Maihi says his tribe won't give up its rights to the river when Genesis goes up for partial sale.
The company is in line for partial privatisation, along with Meridian, after part of Mighty River Power was floated on the stock market in May.
Genesis diverts water from the Whanganui River for its Tongariro Power Scheme - a move detested by local iwi.
Negotiations with the Crown about the iwi's river claim indicate that the river will become its own legal entity, to be managed by the iwi, within a year.
River Maori Trust Board member kaumatua John Maihi said the tribe will not relinquish anything in regards to those negotiations, when the time comes to partially privatise Genesis.