Certain spun-off plans not taken into account

A plan involved in a spin-off which is described in clause (ii), (iii), or (iv) shall not be taken into account for purposes of this paragraph, except that the amount determined under subparagraph (C)(ii) shall be increased by the amount of assets allocated to such plan.

A plan is described in this clause if, after such spin-off, such plan is maintained by an employer who is not a member of the same controlled group as the employer maintaining the original plan.

A plan as described in this clause if, after the spin-off, any employer maintaining such plan (and any member of the same controlled group as such employer) does not maintain any other plan remaining after the spin-off which is also maintained by another employer (or member of the same controlled group as such other employer) which maintained the plan in existence before the spin-off.

For purposes of this subparagraph, the term “controlled group” means any group treated as a single employer under subsection (b), (c), (m), or ( o ).