(1) Approval of an acquisition (whether granted unconditionally or subject to conditions) is effective for such period as the appropriate regulator may specify in writing.
(2) Where the appropriate regulator has specified a period under subsection (1), it may extend the period.
(3) Where the appropriate regulator has not specified a period, the approval is effective for one year beginning with the date -
(a) of the notice given under section 189(4)(a) or (b)(i);
(b) on which the appropriate regulator is treated as having given approval under section 189(6); or
(c) of a decision on a reference to the Tribunal which results in the person receiving approval.