"(4) Where a road passenger transport operator's licence is revoked or withdrawn under an act of an institution of the European Communities in relation to road passenger transport, under an Act of the Oireachtas in relation to road passenger transport, or under any regulation made under section 3 of the European Communities Act 1972 giving effect to an act of an institution of the European Communities in relation to road passenger transport, a licence granted under this Part to the person who held the road passenger transport operator's licence concerned stands revoked.".