In a proceeding for a conversion, the county or municipal corporation and any public agency or public utility supplying electric service or communication service with the county or municipal corporation shall provide by agreement that: at the start or on completion of the conversion, the public agency or public utility has legal title to the electric or communication facilities; and the electric or communication facilities are: a part of the system of the public agency or public utility; and to be used, operated, maintained, and managed by the public agency or public utility as part of its system. Subject to any rules, regulations, or tariffs applicable to the public agency or public utility, the agreement also shall provide for the following: the supplying of or approval by the public agency or public utility of plans and specifications related to the conversion and labor or materials to be used in the conversion; and the performance by the public agency or public utility of all or part of the conversion or improvements and payment to the public agency or public utility for the conversion or improvements. An agreement made under this section must be made before the legislative body of the county or municipal corporation adopts a resolution ordering the conversion. If the proceeding for a conversion is discontinued: any agreement made under this section is void; the petitioners shall reimburse the public agency or public utility for engineering and other preliminary expenses incurred that exceed $2,500; and the petitioners or the county or municipal corporation may not reimburse the public agency or public utility for engineering and other preliminary expenses incurred that are $2,500 or less. If the proposed conversion is completed, any engineering and other preliminary expenses incurred by the public agency or public utility shall be included as part of the cost of the conversion. Before an agreement made under this section takes effect, the Commission may conduct proceedings and shall: determine that the agreement is in the public interest; and issue an order to approve the agreement, disapprove the agreement, or approve the agreement subject to specified conditions.