3(1)The application to a transaction of subsection (1) or (2) of section 485 of the Taxes Act shall not be excluded by the proviso thereto (resident buyer or resident seller) if—
(a)either party to the transaction is a petroleum company or both are petroleum companies ; and
(b)the activities of either or both are or include activities with respect to which the conditions stated in sub-paragraph (2)(a) or (2)(b) below are satisfied ; and
(c)the transaction is part of such activities or is connected with them.
(2)The conditions referred to in sub-paragraph (1) above are—
(a)that profits from the activities are or would be chargeable to overseas tax for which credit could be given under section 498 of the Taxes Act or in pursuance of arrangements having effect by virtue of section 497 of that Act; and
(b)that the activities are exploration or exploitation activities within the meaning of section 38 of the [1973 c. 51.] Finance Act 1973.
4Where both the buyer and the seller are resident in the United Kingdom and the Board, in pursuance of the preceding paragraphs, direct that subsection (1) or subsection (2) of section 485 of the Taxes Act is to apply to the computation of the income, profits or losses of the one, the direction may extend the application of that subsection to the computation of the income, profits or losses of the other, and where it does so adjustments shall be made under subsection (3) of that section accordingly.