(1) In this section -
'relevant trading income' has the same meaning as in section 243A;
'relevant trading loss', in relation to an accounting period of a company, means a loss incurred in the accounting period in a trade carried on by the company, other than -
(a) so much of the loss as is a loss incurred in an excepted trade within the meaning of section 21A, and
(b) [deleted]
(2) Notwithstanding subsection (2) of section 396, for the purposes of that subsection the amount of a loss in a trade incurred by a company in an accounting period shall be deemed to be reduced by the amount of a relevant trading loss incurred by the company in the accounting period.
(3) Where in an accounting period a company carrying on a trade incurs a relevant trading loss, the company may make a claim requiring that the loss be set off for the purposes of corporation tax against income of the company, being -
(a) income specified in section 21A(4),
…