(1)Where section 198 or 199 refers to a person acquiring an interest in shares or ceasing to be interested in shares, that reference in certain cases includes his becoming or ceasing to be interested in those shares by virtue of another person's interest.
(2)Such is the case where he becomes or ceases to be interested by virtue of section 203 or (as the case may be) section 205 whether—
(a)by virtue of the fact that the person who is interested in the shares becomes or ceases to be a person whose interests (if any) fall by virtue of either section to be treated as his, or
(b)in consequence of the fact that such a person has become or ceased to be interested in the shares, or
(c)in consequence of the fact that he himself becomes or ceases to be a party to an agreement to which section 204 applies to which the person interested in the shares is for the time being a party, or
(d)in consequence of the fact that an agreement to which both he and that person are parties becomes or ceases to be one to which that section applies.
(3)The person is then to be treated as knowing he has acquired an interest in the shares or (as the case may be) that he has ceased to be interested in them, if and when he knows both—
(a)the relevant facts with respect to the other person's interest in the shares, and
(b)the relevant facts by virtue of which he himself has become or ceased to be interested in them in accordance with section 203 or 205.
(4)He has the knowledge referred to in subsection (3)(a) if he knows (whether contemporaneously or not) cither of the subsistence of the other person's interest at any material time or of the fact that the other has become or ceased to be interested in the shares at any such time; and " material time " is any time at which the other's interests (if any) fall or fell to be treated as his under section 203 or 205.
(5)A person is to be regarded as knowing of the subsistence of another's interest in shares or (as the case may be) that another has become or ceased to be interested in shares if he has been notified under section 206 of facts with respect to the other's interest which indicate that he is or has become or ceased to be interested in the shares (whether on his own account or by virtue of a third party's interest in them).