464. (1) A merger may not be put into effect save under and in accordance with—

(a) the Summary Approval Procedure and the appropriate provisions of this Chapter where such procedure is employed, or

(b) in the absence of the Summary Approval Procedure being employed for that purpose, the relevant provisions of this Chapter,

but this is without prejudice to the alternative of proceeding under Chapter 1 to achieve the same or a similar result to that which can be achieved by such an operation.

(2) The reference in subsection (3) to a merger taking effect under this Chapter or in section 465 to proceeding under this Chapter includes a reference to a case in which the Summary Approval Procedure and the appropriate provisions of this Chapter are employed for that purpose.

(3) A merger shall not take effect under this Chapter (or any operation to the same or similar effect under Chapter 1) in the absence of the approval, authorisation or other consent, if any, that is required by any other enactment or a Community act for the merger to take effect.