The choice of the members of the tribunal is one of the most, if not the most, important decision taken in the tactical and procedural stage of the reference. The pool from which international arbitrators are selected is both large and small. In theory, anyone can be an arbitrator as there are generally no formal qualifications. In practice, the vast majority of international arbitrators have a legal background or training and a relatively small number of arbitrators undertake the vast majority of arbitrations.
Therefore, a party may have been adjudged by an arbitrator before, a party may have appointed the same arbitrator before, counsel may have appointed the same arbitrator before, or the arbitrator may have some knowledge or affiliation with a party to the arbitration. This is more often the case in specialised fields in which the pool of suitably experienced and skilled arbitrators may be limited.
The twin issues of conflicts of interest and apparent bias arise in relation to arbitrator appointments in this context. Of course, a conflict of interest gives rise to apparent bias so, to a large extent, they are other sides of the same coin. There can be a tension between party autonomy (the right for the parties to “agree on the procedure to be followed by the arbitral tribunal in conducting the proceedings”)1