(1)Subject as provided in subsection (6) below, it shall be the duty of the Corporation so to exercise and perform their functions under this Act as to secure that the combined revenues of the Corporation and all their subsidiaries taken together are not less than sufficient to meet their combined charges properly chargeable to revenue account, taking one year with another.
(2)The Corporation shall—
(a)charge to revenue account in every year all charges which are proper to be made to revenue account including, in particular, proper provision for the depreciation or renewal of assets and proper allocations to general reserve; and
(b)secure that their subsidiaries charge to revenue account in every year all charges which are proper to be made to revenue account including, in particular, proper provision for the depreciation or renewal of assets ;
and in this section " charges properly chargeable to revenue account" shall be construed in accordance with this subsection.
(3)If in any financial year of the Corporation the revenues of the Corporation or (where any companies are in public ownership) the combined revenues of the Corporation and all the publicly-owned companies taken together (as shown in the statement prepared pursuant to section 24(1)(b) below) exceed their charges or (as the case may be) their combined charges properly chargeable to revenue account for that year (as so shown), it shall be incumbent on the Corporation to secure that the excess is, to such extent (if any) as the Secretary of State may direct, applied for such purposes of the Corporation or (as the case may be) of the Corporation and of the said companies as he may direct and, subject to that, is applied for such of those purposes as the Corporation may determine.
(4)The Secretary of State may from time to time determine, with the approval of the Treasury and after consultation with the Corporation, as respects such period as the Secretary of State may so determine, the rate of return on net assets (as for the time being defined by the Secretary of State for the purposes of this subsection) which the Secretary of State considers it is reasonable for the Corporation to achieve in that period; and the Secretary of State may, with the like approval and after such consultation as aforesaid, vary a determination under this subsection as respects any period by a further determination.
(5)The Secretary of State shall give notice to the Corporation of any determination under subsection (4) above.
(6)The Corporation shall conduct their affairs during any period as respects which a determination has been made under subsection (4) above with a view to achieving in that period a rate of return on net assets not less than that specified by the determination as for the time being in force, and the operation of subsection (1) above shall be suspended during any such period.
(7)The Secretary of State may, by order—
(a)substitute for the duty imposed by subsection (6) above a financial duty expressed otherwise than by reference to a rate of return on net assets ; and
(b)for that purpose direct that subsections (4) to (6) above shall have effect subject to such modifications as may be specified in the order and make such other incidental and transitional provisions as appear to the Secretary of State to be necessary or expedient.