Union employees no longer in the union

[Guest flogger]

Is anyone familiar with the rules relating to participation and/or accrual in a DB plan in this situation:

An employer has maintained a union shop, and was contributing to a collectively bargained plan for his union employees. The employer has never had a plan of his own.

This business is no longer "unionized" and he wants to start a qualified plan of his own. The employees are still the same people (ie they are no longer in a union). Can the plan, for eligibility/vesting purposes, assume that these ex-union employees have a date of hire as of their exit from the union?

Likewise, if the new DB plan is a unit credit plan with past service credits, for accrual purposes, can the plan ignore the union employees' service while they were in the union?

Thanks for your thoughts.

[Guest Brian4]

The approach of assuming a date of hire goes contrary to actual history.

For credited service, excluding the union period of service is frequently done for employees transfering out of a bargaining unit in situations where the bargaining unit continues.

The rules on vesting service are more restrictive.