STRIKES at the Port of Auckland are being blamed for the loss of NZ$20 million (US$15.4 million) in annual revenue after its biggest customer Maersk Line diverted one of its services to Tauranga, reports the New Zealand Herald.

It said the loss of Maersk's Southern Star container service amounts to 52 ship calls, or 82,500 containers a year. The report cited the carrier's New Zealand marketing manager Dave Gulik as saying in a separate statement that the industrial action played a role in the decision.

Said Mr Gulik: "The security of their supply chain is of primary importance to our customers, so anything affecting that, or likely to affect that in the future, will come into the equation when we are deciding schedules."

The report said that the Danish shipping line operates the South Star service with Malaysia's MISC Berhad, which has announced its exit the container business in June.