The Maersk shipping line is moving its Southern Star service back to the Port of Tauranga just a year after moving it to Ports of Auckland.
Port of Tauranga chief executive Mark Cairns said it expected this would lead to an increase of about 70,000 6m-equivalent containers going through its facilities each year.
In the six months ended December, the Tauranga port handled more than 381,000 containers.
Mr Cairns said Maersk's decision was one of the first tangible fruits of his company's 10-year deal with Kotahi, a freight company owned by Fonterra and Silver Fern Farms.
"It moves the rotation back to where it was 12 months ago, with the Southern Star calling in Tauranga, so based on our previous experience with the service calling in that rotation, it means probably about 70,000 (6m)-equivalent containers a year.
"That is significant. It's about 8-10 percent of our total container volume."
The company previously estimated the Kotahi deal would be worth more than $5-$6 billion in revenue to the port over the 10 years.