1 On September 29, 1998, WASTE MANAGEMENT, INC., formerly known as USA Waste Services, Inc. (hereinafter referred to as WASTE MANAGEMENT or the Claimant), acting on its own behalf and on behalf of ACAVERDE S.A. de C.V. (hereinafter referred to as ACAVERDE), requested from the Secretary-General of the International Centre for Settlement of Investment Disputes (ICSID), approval of access to the Additional Facility for the Administration of Proceedings by the Secretariat of ICSID (hereinafter referred to as Additional Facility) and, jointly, filed a notice for the institution of arbitration proceedings against the Government of the UNITED MEXICAN STATES (hereinafter referred to as the Government of Mexico), in accordance with Article 2 of the Additional Facility Arbitration Rules (Schedule C).