3.—(1) For the purposes of section 1(3)(b) of the Act (Master Trust schemes: definition), an employer (“A”) is connected with another employer (“B”), and an employer which is a group undertaking of A is connected with an employer which is a group undertaking of B—
(a)where A and B have separate legal identities but are structured so that the economic position of the shareholders of each is, as far as practicable, the same as if they held shares in a single company comprising the combined businesses of A and B;
(b)where A employs scheme members jointly with B;
(c)in respect of active members of the scheme, following a transfer of those members to A from B (but see paragraph (3));
(d)where A holds or controls, or in the previous 6 months has held or controlled, at least 33% of the voting power in B;
(e)where A is, or in the previous 6 months has been, engaged in a joint venture with B.
(2) In paragraph (1)—
“employer” means a person who employs or engages persons who are members of the scheme;
“group undertaking” has the meaning given by section 1161(5) of the Companies Act;
“joint venture” means an arrangement, contractual or otherwise, by which 2 or more parties undertake an economic activity that is subject to joint control.
(3) Where the transfer referred to in paragraph (1)(c) is not a relevant transfer as defined in regulation 2(1) of the TUPE Regulations, A and B (and their respective group undertakings) are connected for no more than 6 months beginning with the date of the transfer.
There are further provisions about relevant transfers in regulation 3 of S.I. 2006/246, which was amended by regulation 5 of S.I. 2014/16