(1)    In this section, “privately owned public utility” includes a cooperative association organized under ch. 185 or 193 for the purpose of producing or furnishing utility service to its members only.

   (2)   A city, village or town served by a privately owned public utility, motor bus or other systems of public transportation rendering local service may contract with the owner of the utility or system for the leasing, public operation, joint operation, extension and improvement of the utility or system by the municipality; or, with funds loaned by the municipality, may contract for the stabilization by municipal guaranty of the return upon or for the purchase by installments out of earnings or otherwise of that portion of the public utility or system which is operated within the municipality and any territory immediately adjacent and tributary to the municipality; or may contract for the accomplishment of any object agreed upon between the parties relating to the use, operation, management, value, earnings, purchase, extension, improvement, sale, lease or control of the utility or system property. The provisions of s. 66.0817 relating to preliminary agreement and approval by the department of transportation or public service commission apply to the contracts authorized by this section. The department of transportation or public service commission shall, when a contract under this section is approved by it and consummated, cooperate with the parties in respect to making valuations, appraisals, estimates and other determinations specified in the contract to be made by it.