On February 26, 2001, the International Centre for Settlement of Investment Disputes (“ICSID” or the “Centre”) received from Enron Corporation and Ponderosa Assets L.P., (the “Claimants”) a Request for Arbitration against the Argentine Republic (the “Argentine Republic” or the “Respondent”). On February 27, 2001, the Centre acknowledged receipt and transmitted a copy of the Request to the Argentine Republic and to the Argentine Embassy in Washington, D.C., in accordance with Rule 5 of the ICSID Rules of Procedure for the Institution of Conciliation and Arbitration Proceedings (“Institution Rules”). The Request concerned certain tax assessments allegedly imposed by some Argentinean provinces in respect to a gas transportation company in which the Claimants participated through investments in various corporate arrangements (the “original” or “stamp tax claim”). In the Request, the Claimants invoke the provisions of the 1991 Treaty between the United States of America and the Argentine Republic Concerning the Reciprocal Encouragement and Protection of Investments (“the Bilateral Investment Treaty”, “Bilateral Treaty” or “Argentina-US BIT”).