PARIS: Trade unions at France’s railway operator SNCF on Saturday called for an indefinite strike from next month that could disrupt train services during the upcoming Christmas holidays. The unions are demanding a moratorium on the dismantling of Fret SNCF, the freight division of the national rail operator, and protesting against the terms and conditions for opening up regional lines to competition. In a joint statement to AFP, the CGT-Cheminots, Unsa-Ferroviaire, Sud-Rail and CFDT-Cheminots unions said the action would begin on December 11.