The CGT union, which represents the majority of dock workers, warned it will stage further protests unless the port authority reviews plans to transfer around 650 container crane operators and maintenance workers from its payroll to private stevedores.
Dockers staged three months of rolling strikes last year in a bid to halt the privatization program at seven public ports, including Le Havre and Marseilles, after the government refused to abandon its reforms.
But the CGT says the privatization plan has been overtaken by the global economic downturn which has reduced container traffic by over 20 percent this year and threatens the job security of dock workers being transferred to private stevedores.
Workers at Marseilles and Nantes Saint-Nazaire staged several strikes in March, casting doubt over their plans to privatize container handling.
The CGT wants to re-negotiate the terms of Le Havre's privatization to tighten guarantees over jobs and wages. It also wants maintenance workers to remain on the port authority's payroll.
The port authority is due to meet on Thursday, April 9, to vote on a strategic plan to implement the reforms.
Le Havre dock workers participated in a 24 hour general strike on March 19 to protest the government's economic policies.
The government says its reforms will improve competitiveness of French ports and boost annual container traffic to 10 million TEUs in 2015 from 3.6 million TEUs in 2007.
The seven ports affected by the reforms are: Le Havre, Marseilles, Rouen, Dunkirk, Nantes Saint-Nazaire, Bordeaux, and La Rochelle.