To the extent and upon such conditions as may be authorized by the superintendent, an insurer may invest in stock and evidences of indebtedness of any housing company or redevelopment company organized under the private housing finance law of this or any other state, or of any corporation organized for the purpose of owning and operating any housing project under laws expressly designed to promote the provision of housing for persons of low and moderate income, or in the securities of any corporation organized under the laws of this or any other state for the purpose of owning, acquiring or holding real property or any interest therein as an investment for the production of income or to be developed or improved for such investment purpose, if all of the stock other than directors' qualifying shares of such housing company, redevelopment company or corporation has been or is to be originally issued to one or more insurers, whether domestic or foreign.   [PL 1969, c. 132, §1 (NEW); PL 1973, c. 585, §12 (AMD).]