220 ILCS 5/8-506

Whenever the Commission, after a hearing had upon its own motion or upon complaint, shall determine that public convenience and necessity require a physical connection for the establishment of a continuous line of communication between any 2 or more public utilities for the conveyance of messages or conversations, the Commission may, by order, require that such connection be made. If such public utilities do not agree upon the division between them of the cost of such physical connection or connections, the Commission shall have authority, after further hearing, to establish such division by supplemental order.