(A1) Subsection (A3) applies in relation to an adverse effect on competition in respect of which the CMA -
(a) has begun an implementation trial under section 161C, or
(b) considers that it is not reasonably practicable to discharge its duty under section 138(2) in accordance with subsection (1) as a result of such an implementation trial in respect of another adverse effect on competition.
(A2) Subsection (1) applies in relation to any other adverse effect on competition.
(A3) Where this subsection applies, the CMA must discharge its duty under section 138(2) before the day specified under section 161D(5)(b)(ii).
(1) Where this subsection applies, the CMA shall discharge its duty under section 138(2) within the period of 6 months beginning with the date on which it publishes the report concerned under section 136.
(2) The CMA may extend, by no more than 4 months, the period within which its duty under section 138(2) is required to be discharged in accordance with subsection (1) if it
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