An individual who makes an election under section 169SC may also elect that, for the purposes of this Act—
The chargeable gain treated as accruing to the individual on a subsequent disposal is the amount resulting from the following steps—
Step 1 Attribute the notional gain to each of the classes of shares in or securities of the company which are the subject of the notional disposal. The attribution must be made, in relation to each class, by reference to the proportion that—
(a)the relevant gains (see section 169N(5)) accruing on the notional disposal in respect of shares or securities within each class bears to
(b)the total amount of relevant gains accruing on the notional disposal.
Step 2 Apportion the amount attributed to each class under Step 1 to the shares or securities of that class which are the subject of the subsequent disposal. The apportionment must be by reference to the proportion that—
(a)the nominal value of the shares or securities of that class which are the subject of the subsequent disposal bears to
(b)the nominal value of shares or securities of that class which are the subject of the notional disposal.
Step 3 The amount resulting from these steps is—
(a)the total of the amounts apportioned to shares or securities under Step 2, but
(b)excluding, in relation to each class of shares or securities, so much of those amounts as would, together with any chargeable gains treated by this section as accruing on previous disposals of shares or securities of that class, exceed the amount attributed to that class under Step 1.
If the subsequent disposal is a disposal by virtue of section 122, the nominal value of shares of a particular class which are the subject of that disposal is to be treated for the purposes of Step 2 of subsection (2) as being equal to the nominal value of shares of that class as are the subject of the notional disposal.