Plans by three of the world's largest container carriers to establish an operational alliance on East - West trade came into effect this week after being cleared by the Federal Maritime Commission (FMC).

Maersk Line, CMA-CGM, and Mediterranean Shipping have teamed up as the P3 Network Vessel Sharing Agreement on routes covering Asia to Europe as well as transpacific and transatlantic routes to the US.

Early estimates by Maersk Line put market control of such an alliance at about 42% on the Asia to Europe route, 24% on the transpacific routes, and 40-42% on the transatlantic route.

The P3 Network will operate a capacity of 2.6m TEU (Twenty-foot Equivalent Units), with an initial combined fleet of 255 vessels on 29 loops.

The group says it will provide customers with more stable, frequent and flexible services, with the combined network offering more weekly sailings than they do individually. It is also expected to reduce the disruptions for customers caused by cancelled sailings.

However, a review by the FMC concluded that the agreement is not likely "to produce an unreasonable increase in transportation cost or an unreasonable reduction in transportation service."

But it said that in case circumstances should change in the future, the three carriers will be subject to special reporting requirements.

Concerns had been expressed last year that the combined fleet is well below the 346 vessels currently in service.