"Port workers...will stop working for 24 hours on Wednesday, March 26, 2008," the union said in a statement.
French port and dock workers have been threatening to take action since the government unveiled plans in January to privatise state-owned ports and make them more efficient.
The union asked France's Transport Ministry earlier this week for a written guarantee that the ports would not be privatised.
But in Friday's statement, the union expressed doubt that they could obtain such assurances.
"This minimum effort seems impossible for the Transport Minister and the government," the union said.
France wants to privatise the loading activities of seven out of nine of the nation's public ports: Marseille, Dunkirk, Le Havre, Rouen, Nantes-Saint-Nazaire, La Rochelle and Bordeaux.
The refinery operations of Total were unlikely to be hit by the strike action, the French oil and gas group said.
"The strike will have an impact on the loading and unloading of ships and that's it," a Total spokesman said.
An 18-day strike at the Fos-Lavera oil hub at the Marseille port last year threatened to shut down some refineries and cause fuel shortages in southeastern France.
Refiners had ample stocks of fuel products as they had been expecting the possibility of a strike since January when France's Prime Minister Francois Fillon announced his reform plan, said one analyst, who declined to be named.
"Refiners have fully replenished their stocks," he said. News of the strike bode badly for Europe's top grain producing country, one grain trader said.
"For the loading of boats this is bad news. With the bad weather we had around mid-March, many shipments have been delayed," the trader said.
"There are many boats which will be arriving this weekend and next week so it won't be good if we have a shorter (work) week than usual," he said.
The port of Rouen, located in northwestern France, is Europe's largest grain export outlet with more than 5 million tonnes shipped a year.
France's shipping industry has long put the government under pressure to streamline the country's ports, but the state has been hamstrung by high union membership among port workers and frequent strikes.
Staff at Marseille's Port Autonome (PAM), which houses the 115,000 barrels-per-day Fos-Lavera oil hub, have held several strikes in the last couple of years, causing disruption to oil refining and other port activities.
French port and dock workers have been threatening to take action since the government unveiled plans in January to privatise state-owned ports and make them more efficient.
The union asked France's Transport Ministry earlier this week for a written guarantee that the ports would not be privatised.
But in Friday's statement, the union expressed doubt that they could obtain such assurances.
"This minimum effort seems impossible for the Transport Minister and the government," the union said.
France wants to privatise the loading activities of seven out of nine of the nation's public ports: Marseille, Dunkirk, Le Havre, Rouen, Nantes-Saint-Nazaire, La Rochelle and Bordeaux.
The refinery operations of Total were unlikely to be hit by the strike action, the French oil and gas group said.
"The strike will have an impact on the loading and unloading of ships and that's it," a Total spokesman said.
An 18-day strike at the Fos-Lavera oil hub at the Marseille port last year threatened to shut down some refineries and cause fuel shortages in southeastern France.
Refiners had ample stocks of fuel products as they had been expecting the possibility of a strike since January when France's Prime Minister Francois Fillon announced his reform plan, said one analyst, who declined to be named.
"Refiners have fully replenished their stocks," he said. News of the strike bode badly for Europe's top grain producing country, one grain trader said.
"For the loading of boats this is bad news. With the bad weather we had around mid-March, many shipments have been delayed," the trader said.
"There are many boats which will be arriving this weekend and next week so it won't be good if we have a shorter (work) week than usual," he said.
The port of Rouen, located in northwestern France, is Europe's largest grain export outlet with more than 5 million tonnes shipped a year.
France's shipping industry has long put the government under pressure to streamline the country's ports, but the state has been hamstrung by high union membership among port workers and frequent strikes.
Staff at Marseille's Port Autonome (PAM), which houses the 115,000 barrels-per-day Fos-Lavera oil hub, have held several strikes in the last couple of years, causing disruption to oil refining and other port activities.