(b) The restriction of subsection (a) hereof shall not apply to the classes of governmental obligations (including obligations secured by mortgages upon real property guaranteed or insured under the National Housing Act, 12 U.S.C. §§ 1701-1750) eligible for minimum capital or surplus to policyholder investments pursuant to the provisions of section one thousand four hundred two of this article nor to investments in shares of other insurance companies pursuant to the provisions of section one thousand four hundred eight of this article.

(c) The limitations of investments set forth in this section shall not apply to mortgage-related securities or securities issued or guaranteed by the Federal Home Loan Mortgage Corporation or the Federal National Mortgage Association; provided, however, that for an insurer maintaining an aggregate investment in excess of seventy percent of its admitted assets as shown by its last statement on file with the superintendent in such securities, the balance of such investments greater than seventy percent thereon shall be limited by and apportioned according to a ratio of one to two respectively, between investment in such securities and investment in government obligations, as that term is defined in paragraph one of subsection (a) of section fourteen hundred four of this chapter.

(d) The superintendent shall not promulgate any rules or regulations to limit or otherwise alter the provisions of paragraph two of subsection (a) of section fourteen hundred one of this article or subsection (c) of this section. The superintendent shall not promulgate any rules or regulations that limit the authority of any insurer to invest in mortgage related securities.