"The situation in North Europe is critical, mainly at the large ports such as Rotterdam, Southampton, and Felixstowe," he said.

"There are manageable delays in Germany, the Baltics, and Scandinavia, and there is some congestion in the Mediterranean, but it is a lot less than in Northern Europe. We expect most services will miss one to two sailings, which will impact available capacity in the second quarter," he said.

"We are doing our utmost not to lose voyages, and if that means we have to omit a port here or there, we will do so because it is important to keep the weekly capacity up as much as possible," Mr Habben Jansen said.

"We speed up when it is useful, and we will look at rerouting ships or changing port rotations to avoid congested ports. We will be looking at alternatives to Rotterdam or the UK ports."

The 24,000-TEU Ever Given ran aground in the southern passage of the Suez Canal on March 23, blocking the vital waterway. By the time the ship was freed six days later, almost 400 ships were at anchor waiting to pass and more than two dozen had already diverted to sail around the southern tip of Africa instead.

Maersk warned in a customer advisory that the acceptance of online bookings would need be determined by port and equipment availability, considering 50 vessels in its 2M Alliance with Mediterranean Shipping Co were delayed for a week when the Evergreen-operated Ever Given ran aground.

"While the impact is still significant in certain areas, we have been successful with a number of mitigation efforts," Maersk said, although the carrier expects the canal closure to impact schedules and port calls well into May.

Sea-Intelligence Maritime Analysis said Mediterranean ports experienced a 60 per cent drop in export capacity during the Suez closure, followed by a sharp recovery as the vessels arrived, but capacity availability was fluctuating as schedules slowly recover.