1.1. The Claimant: The named Claimant is Pac Rim Cayman LLC (also called “Pac Rim Cayman” or “PRC”), a legal person organised under the laws of Nevada, USA, with its principal office at 3545 Airway Drive, Suite 105, Reno, Nevada 89511, USA. The Claimant is wholly owned by Pacific Rim Mining Corporation (also called “Pacific Rim”), a legal person organised under the laws of Canada. In these arbitration proceedings, the Claimant advances several claims against the Respondent both on its own behalf and on behalf of its subsidiary companies, collectively described as the “Enterprises.”

1.2. The Enterprises: The Enterprises are legal persons organised under the laws of the Respondent, namely: (i) Pacific Rim El Salvador, Sociedad Anónima de Capital Variable (also called “PRES”), with its principal office at 5 Avda. Norte, No. 16, Barrio San Antonio, Sensuntepeque, Cabañas, El Salvador; and (ii) Dorado Exploraciones, Sociedad Anónima de Capital Variable (also called “DOREX”), with its principal office at the same address. PRES is the owner of certain rights in the mining areas denominated as “El Dorado Norte,” “El Dorado Sur” and “Santa Rita”; and DOREX is the owner of certain rights in the mining areas denominated as “Huacuco”, “Pueblos” and “Guaco.” These mining areas are located in Las Cabañas and San Vicente, in the northern part of El Salvador.

1.3. ICSID & CAFTA: The Claimant is and has been since 13 December 2007 a national of a Contracting State to the Convention on the Settlement of Investment Disputes (the “ICSID Convention”) and the Dominican Republic-Central America-United States Free Trade Agreement (“DR-CAFTA” or “CAFTA”), in force for the USA as from August 2005. Canada is not a Contracting State to CAFTA or the ICSID Convention; and Pacific Rim, being a Canadian legal person, is not and never has been a national of a Contracting State to CAFTA or the ICSID Convention.