9(1)If a participator in an oil field so elects by notice in writing given to the Board before 1st January 1976 or not later than three months after the end of the earliest chargeable period in which he is a participator in that field, the following provisions of this paragraph shall apply in his case as regards that field; and an election under this sub-paragraph shall be irrevocable.
(2)Where, in computing the assessable profit or allowable loss accruing to the participator in the first or any subsequent chargeable period from the field, any amount attributable to expenditure qualifying for supplement under paragraph (b)(ii) or (c)(ii) of section 2(9) of this Act by virtue of section 3(5) of this Act would, apart from the election, fall to be taken into account under paragraph (b) or (c) of the said section 2(9), then only one-tenth of that amount shall be so taken into account for that period, and, subject to sub-paragraph (3) below, one-tenth of that amount shall be so taken into account in computing the assessable profit or allowable loss accruing to the participator in each of the nine following chargeable periods.
(3)If the winning of oil from the field permanently ceases at a time before the end of the last of those nine chargeable periods, so much of the amount mentioned in sub-paragraph (2) above as at that time has not been taken into account as there mentioned for any chargeable period shall be so taken into account in computing the assessable profit or allowable loss accruing to the participator in the chargeable period in which that time falls.
(4)Sub-paragraphs (2) and (3) above shall, if the participator in his notice so elects and specifies accordingly, apply as if for the references to " one-tenth" and " nine" there were substituted references to one of the fractions mentioned in the left-hand column below and the corresponding number mentioned in the right-hand column, namely—
| one-eighth | seven |
| one-sixth | five |
| one-quarter | three |
| one-third | two. |
(5)The reference in sub-paragraph (2) above to an amount attributable to expenditure qualifying for supplement as there mentioned includes an amount attributable to the expenditure itself as well as an amount calculated by reference to it under paragraph (b)(ii) or (c)(ii) of section 2(9).