Every domestic mutual insurance company, other than a mutual life insurance company, shall invest and keep invested all its funds in accordance with the laws of this Commonwealth relating to the investment of funds of domestic stock fire, stock marine, or stock fire and marine insurance companies. Provided, however, That any mutual insurance company which does not possess a certificate of authority to issue nonassessable insurance policies shall be permitted to invest its funds in assets specified in subsection (a)(3), (6), (7), (8), (9), (10), (11) and (12) of section 518C only after obtaining prior written approval of the Insurance Commissioner.
40 P.S. § 912.1