Reference: Regulation (EU) No 965/2012 Air Operations, Annex III (Part ORO) is available on EASA website.
Aircraft type specific training and operator conversion training is a requirement directed to operators as specified in ORO.GEN.005, therefore the operator is responsible for this training. However, an operator may contract out some activities (e.g. training) as specified in ORO.GEN.205 complemented by AMC1 ORO.GEN.205 and GM1 ORO.GEN.205 and GM2 ORO.GEN.205. Therefore, CCTO can only provide Aircraft type specific training and operator conversion training if contracted by an operator to do so. The operator remains responsible for this training and for the competence of its cabin crew.