215 ILCS 5/131.17

(1) The Director must terminate the registration of any company which demonstrates that it no longer is a member of an insurance holding company system.

(2) The Director may require or allow 2 or more affiliated companies subject to registration to file a consolidated registration statement.

(3) A company which is authorized to do business in this State and which is part of an insurance holding company system may register on behalf of any affiliated company which is required to register under Section 131.13 and to file all information and material required to be filed under this Article unless the Director requires a separate registration by the affiliated company.