One of the important advantages of arbitration proceedings is that the parties can appoint co-arbitrators. Thus, the parties can ensure that those whose impartiality, knowledge and fairness they trust will decide on their dispute. This opportunity raises the question of who the party-appointed arbitrators should be and the criteria by which the parties should appoint the party-appointed arbitrators. 

Since the experience and knowledge of the arbitral tribunal will determine the fate of the award, we have presented below some of the criteria to be considered in the appointment of co-arbitrators. Of course, this enumeration is not exhaustive. Different criteria may emerge according to the characteristics of the case.

1- Independency and Impartiality 

The fact that the parties are empowered to appoint the arbitrator does not mean that the arbitrator will act in favour of the party that has appointed him/her, or that he/she will act as a representative of that party. The co-arbitrators and the presiding arbitrator must be independent and impartial. 
 
2- Expertise

It is important, but not sufficient, that the arbitrators selected are knowledgeable and experienced in arbitration proceedings. The arbitrator should have legal and sectoral knowledge and experience about the dispute. For example, appointment of a co-arbitrator who knows the basic technical terms related to the dispute and lex causae may facilitate the resolution of the dispute.

3- Availability in terms of Time

Another issue to be taken into account in the appointment of an co-arbitrator is whether the arbitrator's workload is suitable to allocate the necessary time for the resolution of the dispute. Especially in complex arbitration proceedings involving technical problems, hundreds of pages of pleadings and evidence may be submitted. Arbitrators are expected to allocate the time necessary for the resolution of the dispute in detail.  In this regard, the Istanbul Arbitration Centre requires arbitrators to declare their workload when they are notified of their appointment and to undertake in writing that they will be able to allocate the necessary time for the proceedings. Failure of the arbitrator to allocate the necessary time may result in the arbitration being protracted and may even result in the denial of the right to be heard.  

4- Language of Arbitration

The Party-appointed arbitrator should have sufficient knowledge of the language of arbitration to conduct a proceeding, to participate in hearings, to express himself/herself comfortably in meetings between arbitrators, and to write the arbitral award.

5- Approach to the Dispute

In some disputes, the validity of the arbitration agreement relied upon by the claimant may depend on the legal understanding of the arbitrators and whether they adopt an approach to the interpretation of the arbitration agreement that is arbitral friendly. Of course, it is not possible to know in advance what the arbitrator will decide on the dispute or to discuss it with him/her. Indeed, it is very difficult to conclude that co-arbitrator who expresses an opinion on the dispute before being appointed as an arbitrator is impartial and unbiased.  Therefore, persons who are proposed to be arbitrators cannot discuss the dispute or express their views with the parties or their representatives. However, if the proposed arbitrator has publications on controversial legal issues, these should be examined. 
Under some institutional arbitration rules, arbitral awards are published unless a party objects. This is the case, for example, under the ICSID and ICC Arbitration Rules. The decisions of an arbitrator in similar disputes may give the parties an idea about the arbitrator's approach to the issues.  

6- Previous Experience

Knowing the attitudes of the arbitrators in other arbitral proceedings in which they have acted as an arbitrator or a counsel may be an important criteria in deciding whether or not to appoint that arbitrator. For this reason, it is very useful to work with lawyers who have previously acted as arbitrators or counsel in arbitral proceedings.