67.—(1) Where it appears to the Board that the joint exercise by two or more authorised undertakers of their powers would be expedient, the Board may by special order make such provisions as appear to it to be necessary or expedient, by the constitution of a joint committee or joint board or otherwise, for the joint exercise by such authorised undertakers of all or any of their powers under this Act or any order thereunder in any area comprising the whole or any part or parts of the respective areas of supply of such authorised undertakers.

(2) Any order made under this section may contain such provisions as may appear to the Board to be necessary or proper for adapting any of the provisions of this Act or any order made thereunder to the circumstances of any joint committee or joint board constituted by such order.