(a) Subject to the superintendent's prior approval, an insurer may establish more than one rating program within the same company for policies of insurance that are subject to section three thousand four hundred twenty-five or section three thousand four hundred twenty-six of this chapter; provided that:

1. (1) each rating program shall apply only to policies newly written on or after the effective date of the rating program but prior to the effective date of any subsequently approved rating program; provided however if an insurer terminates a rating program, then the insurer shall renew the policies that were subject to the terminated rating program in a subsequently approved rating program.
2. (2) the provisions of subsection (f) of section three thousand four hundred twenty-five and subsection (b) of section two thousand three hundred forty-nine of this chapter shall be applied to each rating program to which they are applicable separately.