Upon the certification of the head of the department in which the member is employed, that the experience gained and/or training undertaken by the employee, while on such leave, will be of eventual benefit to that public employer, the Retirement System will approve such leave on a contingent basis. A request for such an approval must be filed with the State Comptroller prior to the commencement of the leave. Approval will not be granted for a leave of more than two years.
N.Y. Comp. Codes R. & Regs. Tit. 2 § 328.2