When ordered by the commission after notice to other interested telephone utilities and the public and due hearing any telephone utility may be required to establish, construct, maintain, and operate any reasonable extension of its existing facilities. If any such extension, however, by any telephone utility of its existing facilities will interfere with the service or system of any other telephone utility, the commission may on petition and after hearing either order the discontinuance of such extension or prescribe such terms and conditions with respect thereto as may be just and reasonable.