((a)) ** Determinative factors** Except as otherwise provided in this section, there is a partial withdrawal by an employer from a plan on the last day of a plan year if for such plan year—

((1)) there is a 70-percent contribution decline, or

((2)) there is a partial cessation of the employer’s contribution obligation.

((b)) ** Criteria applicable** For purposes of subsection (a)—

((1))

((A)) There is a 70-percent contribution decline for any plan year if during each plan year in the 3-year testing period the employer’s contribution base units do not exceed 30 percent of the employer’s contribution base units for the high base year.

((B)) For purposes of subparagraph (A)—

((i)) The term “3-year testing period” means the period consisting of the plan year and the immediately preceding 2 plan years.

((ii)) The number of contribution base units for the high base year is the average number of such units for the 2 plan years for which the employer’s contribution base units were the highest within the 5 plan years immediately preceding the beginning of the 3-year testing period.

((2))

((A)) There is a partial cessation of the employer’s contribution obligation for the plan year if, during such year—

((i)) the employer permanently ceases to have an obligation to contribute under one or more but fewer than all collective bargaining agreements under which the employer has been obligated to contribute under the plan but continues to perform work in the jurisdiction of the collective bargaining agreement of the type for which contributions were previously required or transfers such work to another location or to an entity or entities owned or controlled by the employer, or

((ii)) an employer permanently ceases to have an obligation to contribute under the plan with respect to work performed at one or more but fewer than all of its facilities, but continues to perform work at the facility of the type for which the obligation to contribute ceased.

((B)) For purposes of subparagraph (A), a cessation of obligations under a collective bargaining agreement shall not be considered to have occurred solely because, with respect to the same plan, one agreement that requires contributions to the plan has been substituted for another agreement.

((c)) ** Retail food industry**

((1)) In the case of a plan in which a majority of the covered employees are employed in the retail food industry, the plan may be amended to provide that this section shall be applied with respect to such plan—

((A)) by substituting “35 percent” for “70 percent” in subsections (a) and (b), and

((B)) by substituting “65 percent” for “30 percent” in subsection (b).

((2)) Any amendment adopted under paragraph (1) shall provide rules for the equitable reduction of withdrawal liability in any case in which the number of the plan’s contribution base units, in the 2 plan years following the plan year of withdrawal of the employer, is higher than such number immediately after the withdrawal.

((3)) shall not apply to a plan which has been amended under paragraph (1).

((d)) ** Continuation of liability of employer for partial withdrawal under amended plan** In the case of a plan described in , or a continuation thereof, the plan may be amended to provide rules setting forth other conditions consistent with the purposes of this chapter under which an employer has liability for partial withdrawal.section 404(c) of title 26