Requirements for Amicus Curiae Participation in International Investment Arbitration.

The legal standard on amicus curiae participation in international investment arbitration has been forged by the judicial development of legal rules and, in parallel, the modification of normative sources, such as the ICSID Arbitration Rules. Current and future decisions by arbitral tribunals on the participation of amicus curiae in a given dispute must abide by this consolidated standard. In June 2012, the arbitral tribunal in Joint ICSID Cases No. ARB/10/15 and No. ARB/10/25 released a procedural order, rejecting an amicus petition. This Order contains various deviations from the applicable legal standard and severely restricts the options for amicus participation. The recent attempt to strengthen the legitimacy of international investment arbitration by allowing for greater amicus participation and the acknowledgement of the interdependence of investment law and other areas of international law is thereby put in peril. [ABSTRACT FROM AUTHOR]