Presidents of the Mana and Maori parties met in Auckland on Wednesday signalling a thawing in the relationship.
Media were not invited to the hui but Radio New Zealand understands the discussions were headed by Maori Party co-vice president Ken Mair and Mana Party president Annette Sykes.
A Maori Party statement says the meeting was set up to explore how the parties can work together on a kaupapa by kaupapa (issue by issue) basis.
The statement says merging looks unlikely because of the Mana Party position to work only with certain parties.
Tensions have run high between the two since 2011 when Te Tai Tokerau MP Hone Harawira split from the Maori Party and formed Mana.
Calls to merge were amplified after the Ikaroa-Rawhiti by-election in June, when it became clear that the combined votes of Mana and Maori would have won the seat.