An appeal to another arbitral body within an arbitration proceeding is unusual and, relative to the number of arbitration disputes, exceptional. This phenomenon is therefore barely regulated by law, rarely considered by arbitration rules and only ever mentioned incidentally at most by scholars. As a result, the most important questions relating to internal appeals, as far as they can be identified, remain largely unanswered.
It seems that two legal issues present themselves: (1) which rules govern the arbitral appeal proceedings in the absence of any agreement on this, for example, as regards the time limit for the making of an appeal? and (2) which lex arbitri is applicable if the first and second instance arbitral tribunals are seated in different countries? In relation to the first question, the Swiss lex arbitri turns out to be quite incomplete. Regarding the second question, if the last competent arbitral tribunal has its seat in Switzerland, the Swiss lex arbitri lays claim to the entire arbitral proceeding with regard to mandatory procedural guarantees and the arbitrability of the case.ASA Bulletin