Under Article 16(2) of the ICSID Arbitration (Additional Facility) Rules the proceeding shall remain suspended until the vacancy has been filled. The resigning arbitrator must give reasons for his resignation. The reasons must be of a serious personal or professional nature. The two remaining arbitrators must determine if they accept the resignation or not, in other words, whether the resigning arbitrator has given adeuate justification to them for the resignation. If the resigntion is accepted by them, the new party arbitrator will be selected in the same manner in which it was originally made. Thus, if the party arbitrator was selected by the party (Vz), Vz will select the new arbitrator, but if the resignation is not accepted by them, the new party arbitrator will be selected by the Chairman, i.e. the neutral arbitrator that the two party arbitrators agreed upon in the first place.

Under Article 17 the vacancy must be "promptly filled."

Under Article 18 as soon as a vacancy has been filled, the proceeding shall continue from the point it had reached at the time the vacancy occurred. The newly appointed arbitrator may, however, require "that the oral procedure be recommenced", if it had already been started. This means that where oral testiomny has been given, the new arbitraor may require that the witnesses who gave that oral testimony be recalled to give all or portions of their testimony again, but the new arbitrator will be expected not to abuse this privilege and use it where it is important for him to hear the oral testimony again, for example, where the credibiliy of an important witness is in issue . However, the arbitrator will be expected to bring himslef up to speed primarily by reading the transcripts of the testimonay as well as reading the briefs of the arguments that have been submitted and not rely upon the recalling of the witnesses except, as stated, where needed to resolve a credibility issue.

I don't think any new arbitrator who is appointed again by Vz will accept the position unless he can make an informal committment to the other two arbitrators and to the parties that he can bring himself up to speed in a reasonable amount of time. What is reasonable will depend in large part upon the number of pages of transcript and briefs that he will have to read.

Most interesting will be the stated reaons given by Vz's arbitrator for the resignation. It is my opinion that this resignation and the appointment of a new arbitrator will tend to bring this arbitration to an earlier conclusion than would have been the case without the new appointment. Just my opinion.

For a general discussion of the foregoing points and more, see The ICSID Convention: A Commentary by Schreurer et al., Cambridge University Press (2013).