In a state govt undertaking, a service regulation was existing regarding promotion on basis of seniority cum merit. Here the seniority is inter se seniority of feeder cader. PSU management ammended the regulation that promotion will be on seniority cum merit basis and seniority for promotion will be determined in order to pass the departmental promotional exam i.e. batch wise. In this context, the departmental promotional exam is of qualifying nature only. So I want to know that is it right/legal ammendment in service regulation.