(1)If two or more claims for group relief are made at the same time, for the purposes of sections 139 and 140 treat the claims as made—
(a)in such order as the company making them may elect or the companies making them may jointly elect, or
(b)if no such election is made, in such order as an officer of Revenue and Customs may direct.
(2)For the purposes of Step 3 in subsection (5) of each of sections 139 and 140 the amount of group relief given on a prior claim is determined on the basis that relief is given on the claim before it is given on any later claim.
(3)If the use of the proportion mentioned in section 139(2) or (6), or in section 140(2) or (6), would, in the circumstances of a particular case, produce a result that is unjust or unreasonable, the proportion is to be modified so far as necessary to produce a result that is just and reasonable.