Hawke's Bay Regional Council has bought the last 8% of shares in the Port of Napier that it did not already own.
It began negotiating in March with Manawatu-Whanganui Regional Council to buy the shares, after a proposal was included in both council's long term community plans.
Regional council chairman Alan Dick says the port is a strategic asset for Hawke's Bay.
He says owning all the shares allows for efficient re-structuring of the council's investment portfolio and will provide a greater chance of achieving some economic development goals.
Chief executive Andrew Newman says financially it's far better to have money invested in the port company, which has just undergone a major development, than in cash.
Manawatu-Whanganui Council says a holding company has been set up to manage returns from the sale of the shares.