A branch agreement or a professional or interprofessional agreement may contain provisions less favourable to employees than those applicable to them under an agreement covering a wider territorial or professional area, unless that agreement expressly states that it cannot be derogated from in whole or in part.
Where an agreement or arrangement at a higher level than the agreement or arrangement reached is concluded, the parties shall adapt the provisions of the previous agreement or arrangement that are less favourable to employees if a stipulation in the agreement or arrangement at a higher level expressly so provides.