No stock company formed under chapters 17 to 33 of this title (s. 17:17-1 et seq.) shall create more than one class of stock except, however, that preferred or nonvoting stock, or both, may be issued if the amount of the stock so issued shall not at any time exceed the amount of common or voting stock, or both, then issued and outstanding, but preferred stock may be issued without limitation when such preferred stock is to be purchased or loaned upon by any corporation, association or agency created by or organized under any law of the United States of America.
N.J.S. § 17:25-1