Third Party Participation in Investor-State Arbitration: New Trends in ICSID Rules and UNCITRAL Transparency Rules

Arbitration is the most common method for resolving international investment disputes. The significant development of transparency in investment arbitration has led this notion to play a crucial role in the field of third party participation. The issue of third party participation in international investment arbitration is subject to controversy and different interpretations. This is a controversial area among national arbitration laws. Rules of different arbitration institutions have also taken different views as to whether third party can participate in international arbitration. ICSID Arbitration Rules, as amended in 2006, and UNCITRAL Transparency Rules 2013 have considered new trends and perspectives in this regard. A number of ICSID tribunals have also adhered to this trend by considering a modern approach. This Article aims to examine these Rules and related case law in the light of third party participation and concludes that there is a tendency towards the recognition of third party participation in investor-State arbitration in order to meet jurisdictional objectives and to bring transparency.