The strikers want job guarantees as part of a port reform and are also protesting against President Nicolas Sarkozy's pension reforms that raise the retirement age to 62 from 60, which has already sparked several waves of nationwide protests.
The strikes at Fos-Lavera, France's largest oil port, has helped squeeze the nation's fuel supply, creating fears it could run short of both crude oil and refined products.
Of the ships unable to dock because of the strike, 29 carry crude oil and 18 refined oil products. Ten carry butane gas and 4 are loaded with chemicals.