The chief administrative officer of each college is authorized to approve the employment of a retired person in the professional service at such college, and shall report such approval of employment to the chancellor. The chancellor may require submission by a college of applications for such re-employment for his approval when he deems it in the best interest of the State University. The chancellor or designee is authorized to approve employment of a retired person in the professional service by system administration, and to approve employment of a retired person as a chief administrative officer. Approval for the employment of retired persons shall be granted only when such approval would be in accordance with the several provisions and limitations of the act.