610 ILCS 65/1
Any railroad corporation organized and existing under the laws of this State or existing by consolidation of different railroad corporations under the laws of this State and any other State, which owns more than fifty per cent of the capital stock of another corporation which capital stock it is authorized to own, is authorized by action of its board of directors to guarantee the payment of the principal and/or interest of the bonds or other obligations of such other corporation. Any such railroad corporation which jointly with other railroad corporations owns more than fifty per cent of the capital stock of another corporation which capital stock it is authorized to own, is authorized by action of its board of directors to join with such other railroad corporations in guaranteeing the payment of the principal and/or interest of the bonds or other obligations of such other corporation whose capital stock is so owned.
610 ILCS 65/1