56It must be observed that measures granting an advantage only to certain undertakings determined by reference to their place of establishment are, prima facie, selective (see, to that effect, judgments of 19 September 2000, Germany v Commission, C‑156/98, EU:C:2000:467, paragraph 23, and of 6 September 2006, Portugal v Commission, C‑88/03, EU:C:2006:511, paragraphs 60 and 61).