19. (1) An acquirer may make an open offer conditional as to the minimum level of acceptance:
Provided that where the open offer is pursuant to an agreement, such agreement shall contain a condition to the effect that in the event the desired level of acceptance of the open offer is not received the acquirer shall not acquire any shares under the open offer and the agreement attracting the obligation to make the open offer shall stand rescinded.
2. Where an open offer is made conditional upon minimum level of acceptances, the acquirer and persons acting in concert with him shall not acquire, during the offer period, any shares in the target company except under the open offer and any underlying agreement for the sale of shares of the target company pursuant to which the open offer is made.