220 ILCS 30/8
When a complaint has been filed as provided in Section 7, the Commission shall proceed, after reasonable notice to the suppliers concerned, to a hearing to determine which of the suppliers is entitled or should be permitted under this Act to furnish the proposed service. The Commission shall first determine whether temporary service should be authorized and may issue a temporary authorization to a supplier permitting the making of extensions and furnishing of service while the dispute is pending. The Commission shall then make its determination as to which supplier is entitled or should be permitted under this Act to furnish the proposed service. In making this determination, the Commission shall act in the public interest and shall give substantial weight to the consideration as to which supplier had existing lines in proximity to the premises proposed to be served, provided such lines are adequate. In addition, the Commission may consider, but with lesser weight, (a) the customer's preference as to which supplier should furnish the proposed service, (b) which supplier was first furnishing service in the area, (c) the extent to which each supplier assisted in creating the demand for the proposed service, and (d) which supplier can furnish the proposed service with the smaller amount of additional investment. The Commission, however, shall give no weight or consideration to the fact that any supplier has or has not been issued a certificate of public convenience and necessity in the area proposed to be served.
After making its determination, the Commission shall make findings of fact and render its decision as to which supplier is entitled or should be permitted to furnish the proposed service. The decision of the Commission constitutes an authorization to that supplier to render such service and revokes any temporary authorization granted by the Commission while the dispute was pending.
220 ILCS 30/8