(a) Each agency shall select competing employees for release from a competitive level under this part in the inverse order of retention standing, beginning with the employee with the lowest retention standing on the retention register. An agency may not release a competing employee from a competitive level while retaining in that level an employee with lower retention standing except:

(1) As required under § 351.606 when an employee is retained under a mandatory exception or under § 351.806 when an employee is entitled to a new written notice of reduction in force; or

(2) As permitted under § 351.607 when an employee is retained under a permissive continuing exception or under § 351.608 when an employee is retained under a permissive temporary exception.

(b) When employees in the same retention subgroup have identical service dates and are tied for release from a competitive level, the agency may select any tied employee for release.