(a) General. The PBGC shall approve an alternative allocation method or modification to an allocation method if the PBGC determines that adoption of the method or modification would not significantly increase the risk of loss to plan participants and beneficiaries or to the PBGC.

(b) Criteria. An alternative allocation method or modification to an allocation method satisfies the requirements of paragraph (a) of this section if it meets the following three conditions:

(1) The method or modification allocates a plan's unfunded vested benefits, both for the adoption year and for the five subsequent plan years, to the same extent as any of the statutory allocation methods, or any modification to a statutory allocation method permitted under subpart B.

(2) The method or modification allocates unfunded vested benefits to each employer on the basis of either the employer's share of contributions to the plan or the unfunded vested benefits attributable to each employer. The method or modification may take into account differences in contribution rates paid by different employers and differences in benefits of different employers' employees.

(3) The method or modification fully reallocates among employers that have not withdrawn from the plan all unfunded vested benefits that the plan sponsor has determined cannot be collected from withdrawn employers, or that are not assessed against withdrawn employers because of section 4209, 4219(c)(1)(B) or 4225 of ERISA.

(c) PBGC action on request. The PBGC's decision on a request for approval shall be in writing. If the PBGC disapproves the request, the decision shall state the reasons for the disapproval and shall include a statement of the sponsor's right to request a reconsideration of the decision pursuant to part 4003 of this chapter.