This excerpt taken from the PNC 10-K filed Mar 2, 2009.
AND CESSATION OF PARTICIPATION
An Employee who participates in the Pension Plan is eligible to participate in this Plan if the Employee has Excess Benefits. If an Employee ceases to participate in the Pension Plan, the Employee is no longer eligible to participate in this Plan. Such Participants Account will be frozen as of the date he or she ceases participation, except that interest will continue to be credited under Section 3 of the Plan. Such frozen benefit will be payable at the same time and in the same manner as benefits otherwise payable under the Plan.