Operations at French state-run ports have been disrupted since mid-April by a rolling weekly strike.
The government argues that the reform will boost the private sector's role, creating new jobs and boosting efficiency.
The strategic Fos-Lavera port, with an annual oil traffic of 64.2 million tonnes, supplies crude to eight refineries in southeast France with a production capacity of around 800,000 barrels per day.
Crude from the terminal also supplies the 310,000 bpd Miro refinery in Germany and the 68,000 Cressier refinery in Switzerland.
A three-week strike in March 2007 threatened to shut down some refineries and caused a fuel shortage in southeastern France.
Refiners are looking to keep a low profile and say the dispute is between the government and the unions and has so far not affected their operations.
Work at French state-run ports is strictly divided between private sector cargo handlers and public sector authorities which manage harbour infrastructure, including the cranes used to load and unload ships and the crane drivers.
Freight handlers and shipping groups have long complained that the division has held back investment in infrastructure, leads to severe inefficiency and has contributed to the steady decline in market share seen by French ports in recent years.