A strike over pension reforms by harbour pilots has largely paralysed traffic to the Belgian ports of Antwerp and Zeebrugge.
The pilots, who lead ships into the two ports, are demanding their profession is exempted from government plans to add two years to the retirement age.
Around 60 ships were blocked by the all-night strike and go-slow actions on both Monday and Tuesday.
Antwerp, one of the biggest ports in the world, said the strike is costing about a million euro (£838,240) an hour.
The government is expected to announce the full pension plans later on Tuesday.