All depends on the form of termination i.e. whether it is a resignation, a dismissal/redundancy, a dismissal for serious or gross misconduct, or a mutual termination agreement.
In general, the applicable collective bargaining agreement would set out for more favorable provisions in regard to severance payment.
Pursuant to the French Employment Code, the minimum compensation for dismissal should be paid to any employee who has accrued eight months’ service within the company and amounts to ¼ of a month’s salary per year of service until 10 years of service and 1/3 of a month’s salary from 10 years of service.