The port plans to contract with three stevedore companies for its Fergusson and Bledisloe container terminal operations, it said in a statement.
"We've weighted up all the options and we believe this is the best decision for the future of the port," said Tony Gibson, chief executive. "The decision will reassure the wider market and customers that we plan to achieve a sustainable lift in the port's competitiveness as soon as possible."
Gibson said the redundant workers would be encouraged to apply for new positions with the contractors.
The Maritime Union has vowed to fight on and its dispute has already garnered support from unionised workers at other ports and from international port worker groups.
"This is by no means the end of our campaign for secure work," said Garry Parsloe, president of the Maritime Union. "We call on Mayor Len Brown to not let this happen on his watch in his time as leaders of this city and owner of the port."
Brown said he is restrained by legislation from intervening, the NZ Herald reported.
Earlier this week the union gave 14 days notice of another week of strike action to begin on March 16, which would only have been lifted if a settlement was reached. That would make four weeks of continuous action, on top of several earlier strikes and a lock-out by port management.
The dispute has cost the port contracts with shipping line Maersk and dairy exporter Fonterra Cooperative Group, who have shifted some services to Port of Tauranga and Port of Napier.