California Code, Financial Code - FIN § 31220

(a) Any commercial bank, industrial bank, or trust company organized under the laws of this state may, with the prior approval of the commissioner, acquire and hold securities issued by a licensee;  provided, however, that the aggregate amount of securities issued by licensees which are held by the commercial bank, industrial bank, or trust company shall not at any time exceed 2 1/2 percent of the shareholders' equity of the commercial bank, industrial bank, or trust company.  This subdivision shall not apply to any loan or other extension of credit made by a commercial bank or industrial bank organized under the laws of this state to a licensee in accordance with the Banking Law (Division 1 (commencing with Section 99)).

(b) Any savings association organized under the laws of this state may, with the prior approval of the commissioner, acquire and hold securities issued by a licensee;  provided, however, that the aggregate amount of securities issued by licensees which are held by such savings association shall not at any time exceed 1/2 percent of the total outstanding loans of such savings association.

(c) Any insurance company admitted to transact insurance business in this state may, with the approval of the Insurance Commissioner, acquire and hold securities issued by a licensee;  provided, however, that the aggregate amount of securities issued by licensees which are held by such insurance company shall not at any time exceed 2 1/2 percent of the unassigned surplus of such insurance company.

(d) Any public utility licensed or regulated by the Public Utilities Commission may, with the approval of the Public Utilities Commission, acquire and hold securities issued by a licensee;  provided, however, that the aggregate amount of securities issued by licensees which are held by such public utility company shall not at any time exceed 1/2 percent of the total assets of such public utility company.