Oregon Revised Statutes Utility Regulation § 756.518

(1) Except as otherwise provided the provisions of ORS 756.500 to 756.610 apply to and govern all hearings upon any matter or issue coming before the Public Utility Commission under any statute administered by the commission, whether instituted on the application, petition or complaint of others or initiated by the commission, together with the orders of the commission therein and the review thereof in the courts.

(2) Upon request of any party in a major proceeding before the commission, the commission shall afford the parties an opportunity for oral argument before a final order is issued. There must be a quorum of the commission present at the time the oral argument is made. The commission shall adopt rules that establish criteria for determining which proceedings give rise to a right to oral argument under this subsection. In addition, the commission may adopt rules governing participation in oral arguments, cross-examination of witnesses, draft or proposed orders or such other matters as the commission deems appropriate.