The International Container Lines Committee warns that Ports of Auckland could lose more business as a result of on-going industrial action.
Maritime Union members at the port began working to rule for a week on Wednesday, and plan to strike for a week from 24 February.
The ICLC says the dispute is extremely frustrating for shipping companies, and is costly for their customers and for the economy as a whole.
Fonterra and Maersk Shipping have already quit Ports of Auckland for Tauranga, blaming the industrial dispute.
ICLC chair Julian Bevis told Morning Report that exporters and importers need a reliable supply chain and they will be forced to look elsewhere if they can't get it in Auckland.
Mr Bevis said a solution must be reached as soon as possible.
The Maritime Union says it also wants a productive port in Auckland, but not at the expense of job security for its members.
National president Garry Parsloe says the members would stop striking if the port company took part in mediation and negotiated over a collective employment agreement.
He says this week's partial strike is not interrupting port services.
Ports of Auckland says Mr Parsloe statement that "Ports of Auckland don't turn up to mediation" is incorrect.
The last mediation was held on Friday and lasted five hours.
The company says Mr Parsloe did not attend the meeting, which was adjourned. No new date for mediation has been set.
The company says it was noted by the mediators that it was difficult to schedule the next mediation session with the ongoing strike action by the union.