Liability of substantial employer for withdrawal from single-employer plans under multiple controlled groups

Except as provided in subsection (d), the plan administrator of a single-employer plan which has two or more contributing sponsors at least two of whom are not under common control— Except as provided in subsection (c), any one or more contributing sponsors who withdraw, during a plan year for which they constitute a substantial employer, from a single-employer plan which has two or more contributing sponsors at least two of whom are not under common control, shall, upon notification of such contributing sponsors by the corporation as provided by subsection (a), be liable, together with the members of their controlled groups, to the corporation in accordance with the provisions of section 1362 of this title and this section. The amount of liability shall be computed on the basis of an amount determined by the corporation to be the amount described in section 1362 of this title for the entire plan, as if the plan had been terminated by the corporation on the date of the withdrawal referred to in subsection (a)(1) multiplied by a fraction— If the plan terminates under section 1341(c) or 1342 of this title within the 5-year period commencing on the day of withdrawal, the corporation shall— The provisions of this subsection apply in the case of a withdrawal described in subsection (a), and the provisions of subsections (b) and (c) shall not apply, if the corporation determines that the procedure provided for under this subsection is consistent with the purposes of this section and section 1364 of this title and is more appropriate in the particular case. Upon a showing by the plan administrator of the plan that the withdrawal from the plan by one or more contributing sponsors has resulted, or will result, in a significant reduction in the amount of aggregate contributions to or under the plan, the corporation may— The corporation is authorized to waive the application of the provisions of subsections (b), (c), and (d) of this section whenever it determines that there is an indemnity agreement in effect among contributing sponsors under the plan which is adequate to satisfy the purposes of this section and of section 1364 of this title.