Ins. Code, § 1192

Excess funds investments may be made in:

(a) Interest-bearing obligations issued by a nonaffiliate institution, as defined in paragraph (5) of subdivision (f) of Section 1196.1, organized under the laws of any state, or of the United States, or of the District of Columbia, or of the Dominion of Canada or of any province of the Dominion of Canada, or interest-bearing obligations registered with the Securities and Exchange Commission and publicly traded issued by an affiliate corporation organized under the laws of any state, or of the United States, or of the District of Columbia, or of the Dominion of Canada or of any province of the Dominion of Canada, or interest-bearing obligations issued by an authority established pursuant to the California Industrial Development Financing Act provided for in Title 10 (commencing with Section 91500) of the Government Code, to which the corporation is obligated with respect to payment, or

(b) Equipment trust obligations or certificates, or other adequately secured instruments, evidencing an interest in or lien upon transportation equipment used or to be used by a common carrier or common carriers and a right to receive determined portions of fixed obligatory payments for the use or purchase of this equipment, when the obligations, certificates, or instruments are issued by a corporation specified in subdivision (a) or are unconditionally guaranteed or assumed by the corporation as to principal and as to interest or dividends and as to the payment of the fixed obligatory payments or the payment of the determined portions thereof.