(a) An insurer may invest in obligations which are secured by:
(1) An assignment of a right to receive rental, charter hire, purchase or other payments for the use or purchase of real or personal property adequate to return the investment and payable or guaranteed by 1 or more governmental units or instrumentalities whose obligations would qualify for investment under § 1306 of this title (public obligations) or 1 or more institutions whose obligations would qualify for investment under § 1308(a) or under § 1308(c)(2), (4) or (5) of this title (corporate obligations); and
(2) A mortgage on or secured interest in such real or personal property.
(b) No insurer shall make an investment pursuant to this section in obligations, other than those of institutions, if the aggregate amount so invested will exceed 10% of its assets or if the aggregate amount so invested as to which such rental, charter hire, purchase or other payments are payable or guaranteed by any 1 governmental unit or instrumentality or any 1 institution will exceed 5% of such assets. No insurer shall make any investment pursuant to this section in obligations of or in any affiliate (as defined in § 5001 of this title).