Amicus Curiae Participation in ICSID Arbitration: Evolution and Refinement

The ICSID (International Centre for Settlement of Investment Disputes) began allowing amicus curiae participation in international investment arbitrations on the initiative of petitioners. As amicus curiae participation continued to grow, the existing rules were insufficient to provide clear guidance to amicus curiae petitioners and arbitral tribunals, and the ICSID updated its rules on amicus curiae participation again in 2022. While the new rules make some progress in strengthening amicus curiae eligibility and preventing procedural burdens, they still lack an effective confidentiality regime, and tribunals do not have an effective basis for how they should deal with potential cost increases arising from amicus curiae participation. Therefore, ICSID needs to continue to refine the protection of confidential or protected information, and to establish as soon as possible a system for amicus curiae to share the costs of the proceeding and a system of security for costs.