If the tribunal is to consist of two arbitrators and an umpire:
- a each party shall appoint one arbitrator not later than 14 days after service of a request in writing by either party to do so;
- b the two so appointed may appoint an umpire at any time after they themselves are appointed and shall do so before any substantive hearing or forthwith if they cannot agree on any matter relating to the arbitration, and if the two said arbitrators do not appoint an umpire within 14 days of one calling upon the other to do so, the President shall, on the application of either arbitrator or of a party, appoint the umpire;
- c the umpire shall attend any substantive hearing and shall following his appointment be supplied with the same documents and other materials as are supplied to the other arbitrators;
- d the umpire may take part in and, if the original arbitrators so agree, chair the hearing and deliberate with the original arbitrators;
- e decisions, orders and awards shall be made by the original arbitrators unless and until they cannot agree on a matter relating to the arbitration. In that event they shall forthwith give notice in writing to the parties and the umpire, whereupon the umpire shall replace them as the tribunal with power to make decisions, orders and awards as if he were the sole arbitrator.
I dansk ret støder praktikeren nok ikke mindst ind i en umpire-løsning i voldgiftsklausuler indenfor den maritime sektor. 359359. Se som et nyere eksempel herpå voldgiftsklausulen i U 2013.2238 Ø, der for domstolene handlede om, hvorvidt et konkursbo var bundet af voldgiftsaftale. Hovedaftalen var et certeparti, og voldgiftsklausulen heri lød: »All disputes arising out of this contract which cannot be amicably resolved shall be referred to arbitration in London. Unless the parties of this contract agree upon a sole arbitrator the reference shall be for 2 (two) arbitrators, one to be appointed by each of the parties. The arbitrators shall be commercial men, and the umpire if appointed, in the event of disagreement between two arbitrators, shall be a legal man, and shall be members of the London Maritime Arbitrators' Association. ...« Fra ældre retspraksis kan henvises til U 1957.546 H, der ligeledes omhandlede en tvist vedrørende et certeparti: »Any dispute arising under the Charter to be referred to arbitration in Copenhagen one Arbitrator to be nominated by the Owners and the other by the Charterers, and in case the Arbitrators shall not agree then to the decision of an Umpire to be appointed by them, the award of the Arbitrators or the Umpire to be final and binding upon both parties.« Afgørelsen omtales nærmere nedenfor under 3.3.
Visse forfattere er meget kritiske overfor umpire modellen. Vedrørende engelsk ret kan henvises til Merkin & Flannery: Arbitration Act 1996 (5. udg., 2014), der s. 79 anfører, at »(t)he practice ought not be to encouraged as an efficient dispute resolution process. It is hoped that at the next