(1) Where a company incurs qualifying expenditure on the purchase of capacity rights and, before the end of the writing-down period, any of the following events occurs -
(a) the rights come to an end without provision for their subsequent renewal or the rights cease altogether to be exercised;
(b) the company sells all those rights or so much of them as it still owns;
(c) the company sells part of those rights and the amount of net proceeds of the sale (in so far as they consist of capital sums) are not less than the amount of the qualifying expenditure remaining unallowed;
no writing-down allowance shall be made to that company for the chargeable period related to the event or for any subsequent chargeable period.
(2) Where a company incurs qualifying expenditure on the purchase of capacity rights and, before the end of the writing-down period, either of the following events occurs -
(a) the rights come to an end without provision for their subsequent renewal or the rights cease altog
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