29 U.S.C. § 1364: Liability on termination of single-employer plans under multiple controlled groups

This section applies to all contributing sponsors of a single-employer plan which has two or more contributing sponsors at least two of whom are not under common control at the time such plan is terminated under section 1341(c) or 1342 of this title, or who, at any time within the 5 plan years preceding the date of termination, made contributions under the plan. the numerator of which is the amount required to be contributed to the plan for the last 5 plan years ending prior to the termination date by persons in such controlled group as contributing sponsors, and the denominator of which is the total amount required to be contributed to the plan for such last 5 plan years by all persons as contributing sponsors,