The Port of Tauranga's share price fell after Ports of Auckland announced that shipping line Maersk would resume its Southern Star service to Auckland, starting from July.
The Southern Star service moved from Auckland to Tauranga at the height of the port's bitter dispute with the Maritime Union in December, 2011.
"This new service, with bigger ships and larger exchanges of containers cements our position as the import port of choice," Ports of Auckland chief executive Tony Gibson said.
Gibson said in a statement that Maersk's return would require increased productivity "something our work over the last year has shown we can deliver''.
Ports of Auckland had been working to lift productivity by restructuring, improving processes, and by implementing a new shift and roster system for over a third of stevedores, he said.