Article 391 of Regulation (EU) No 575/2013 (CRR) doesn't refer to any EC implementing decision to be adopted in order to determine whether a private or public undertaking, including its branches, established in a third country can be considered an "institution" for large exposures purposes. It is thus for the institution and supervisory authority concerned to decide whether an entity fulfils the equivalence requirement set out in Article 391 of CRR. In doing so, the EC implementing decision on equivalence of prudential supervisory and regulatory requirements applicable to third country institutions adopted according to other provisions of CRR may be used as guidance (see Commission Implementing Decision, 12 December 2014, n. 2014/908/EU).

Disclaimer:

This question goes beyond matters of consistent and effective application of the regulatory framework. A Directorate General of the Commission (Directorate General for Financial Stability, Financial services and Capital Markets Union) has prepared the answer, albeit that only the Court of Justice of the European Union can provide definitive interpretations of EU legislation. This is an unofficial opinion of that Directorate General, which the European Banking Authority publishes on its behalf. The answers are not binding on the European Commission as an institution. You should be aware that the European Commission could adopt a position different from the one expressed in such Q&As, for instance in infringement proceedings or after a detailed examination of a specific case or on the basis of any new legal or factual elements that may have been brought to its attention.