N.Y. Comp. Codes R. & Regs. tit. 2 § 39.6
A political subdivision may cause certificates of participation issued in connection with one or more of its installment purchase contracts to be sold at public sale. Such certificates of participation shall be sold to the bidder offering the lowest interest cost as computed in accordance with the net interest cost method, taking into consideration any premium or discount, or the actuarial or true interest cost method, whichever is specified in the notice of sale. The notice of such sale must be circularized in accordance with any rule or order prescribed by the State Comptroller pursuant to paragraph d of section 57.00 of the Local Finance Law for the circularization of notices for the sale of bonds. Where the notice of sale provides that bids shall be awarded based on net interest cost, the notice shall also require that the interest rate for each maturity shall not be less than the interest rate for any prior maturity. The notice of sale must be circularized not less than four nor more than 15 days, Sundays excepted, before the date fixed for the public sale unless the notice provides for a supplemental notice of sale in accordance with the procedure for the sale of bonds in paragraph (d) of section 58.00 of the Local Finance Law.
N.Y. Comp. Codes R. & Regs. Tit. 2 § 39.6