a. If the comptroller, in his or her discretion, decides to permit amortization of employer contributions, then, on or about October fifteenth, two thousand three, on the basis of the annual actuarial valuation provided for in this chapter, the comptroller shall determine the amount (exclusive of payments for group term life insurance, deficiency payments, adjustments relating to prior fiscal years' obligations and obligations pertaining to retirement incentives or any other obligations that a participating employer is permitted to pay on an amortized basis) of the annual contribution for a participating employer pursuant to section twenty-three-a of this article due for the fiscal year ending March thirty-first, two thousand five, calculated as of December fifteenth, two thousand four. The amount by which such contribution exceeds seven percent of the estimated pensionable salary base for the fiscal year ending March thirty-first, two thousand five shall be the "amount eligible for amortization". An amount up to the "amount eligible for amortization" may be amortized over a ten-year period at eight percent interest per annum, with the first of ten equal payments payable on February first, two thousand six provided, however, that on or before September first, two thousand four, the comptroller, in his or her discretion, may establish a fixed rate of interest per annum to be applied to the amounts eligible for amortization of all employers, which more closely approximates a market rate of return on taxable fixed rate securities with similar terms issued by comparable issuers. b. A participating employer, may, in lieu of paying its entire February first, two thousand five bill, pay a lesser amount on February first, two thousand five which shall be the entire February first, two thousand five bill, calculated pursuant to section twenty-three-a of this article (without reference to this section) less the "amount eligible for amortization". b-1. A participating employer making a payment pursuant to subdivision b of this section shall pay on February first, two thousand six an amount determined by the comptroller by adding the following two amounts together:

1. (1) the entire February first, two thousand six bill, calculated pursuant to section twenty-three-a of this article (without reference to this section), less the "amount eligible for amortization" determined pursuant to section seventeen-c of this article, if applicable; and
2. (2) the first annual installment of the "amount eligible for amortization" determined pursuant to this section. c. The remaining amortized payments shall be due and payable on February first of each year during the amortization period. The comptroller shall have the authority to permit the pre-payment of the remaining balance of the "amount eligible for amortization," subject to the following:
3. (1) on or before November fifteenth, two thousand four in addition to the amount due for the current year billing, the comptroller shall advise the participating employer of the total amount due and be authorized to accept pre-payment in full of said amount by February first, two thousand five.
4. (2) on or before each November fifteenth thereafter, in addition to the amount due for the current year billing and for the payment of the annual amortized installment, the comptroller shall advise the participating employer of the total amount still outstanding and be authorized to accept the pre-payment of any balance remaining to be paid by February first of the succeeding year.