Airlines – regulated by the Member States
A list of aircraft operators that perform an aviation activity listed in Annex I to Directive 2003/87/EC on or after 1 January 2006 appears in Commission Regulation (EU) No. 394/2011. The list also specifies the administering EU Member State for each aircraft operator.
A link to Regulation 394/2011 is available here:
If an air carrier is not listed in the above Regulation, then the appropriate authority in the Member State where that air carrier has the most frequent services should be contacted for guidance.
This list provides the information about which Member State will be regulating a particular aircraft operator.