For the purposes of this Regulation, the first admission to trading of a share on a regulated market referred to in Article 40 of Directive 2004/39/EC shall be considered to take place at a time when one of the following conditions applies:
(a) the share has not previously been admitted to trading on a regulated market;
(b) the share has previously been admitted to trading on a regulated market but the share is removed from trading on every regulated market which has so admitted it.