The US Federal Maritime Commission (FMC) has told its staff to prepare an order to force the carriers to release the data and information, reports Newark's Journal of Commerce.

The Shipping Act permits the FMC to order carriers to provide information relevant to the agency's monitoring of agreements in exchange for the industry's antitrust immunity.

If the carriers don't provide the requested data and information, the FMC can void the agreement.

The agency declined to comment on what type of data and information carriers hadn't handed over for regulators to use in monitoring the Pacific Port Operational Improvement Agreement.

The PPOIA allows terminal operators and equipment managers to work with carriers, truckers and railways to alleviate congestion that crippled US ports in late 2014 and early 2015.

Individual commissioners have accused carriers and their vessel-sharing alliances of creating port congestion by inundating marine terminals with cargo from huge ships, and profiting from resulting congestion by imposing fines.

Denying this, the World Shipping Council, representing carriers, said congestion has multiple causes, but mega ships and alliances were not among them.

Shippers, truckers and trade associations want the FMC to stop terminals imposing demurrage charges for late pickup of containers and carriers' per diem detention fees for late return of equipment.

In response, the FMC released a report that urged the industry to provide evidence of any charges that might be considered unreasonable.