Work stoppage scheduled to begin Friday at Marseille and Le Harve, The Journal of Commerce Online reports
Workers at Marseilles, Frances leading will launch their fourth straight weekend of strikes because the latest talks with port bosses have failed.
Four more days of strikes over its dispute on early retirement provisions would begin on 4 February, the ports and docks federation of the CGT union confederation told Fairplay.
The government "cannot remain closed and impose its will in deciding what can be discussed and what cannot", the CGT warned in a communiqué.
The union wants port workers who have been subject to physical hardship to have the option of retiring up to four years before the official retirement age.
The Communist-led CGT, the biggest docker union, last week called for a third successive weekend stoppage as leading ports struggle to clear up a backlog of cargo built up during the previous strikes.
The strikes completely or partially close down France's major ports, including Marseille and Le Havre, the nation's biggest container hub.
The union said the strike, like previous stoppages, would not affect oil traffic and passenger ships, but would halt mainly container traffic and bulk shipments.