An arrangement intended for use in corporate restructuring situations where a participating employer in a multi-employer defined benefit (DB) pension scheme stops participating in the scheme. The purpose of a regulated apportionment arrangement is to apportion the departing employer's share of the employer debt that would otherwise be due to the scheme among one or more of the remaining participating employers. Certain prescribed conditions must be met, including that the scheme must have entered a Pension Protection Fund assessment period or that the trustees consider there is a reasonable likelihood the scheme will enter an assessment period in the next 12 months. The agreement of the Pensions Regulator is also needed.