On 6 June 2003, El Paso Energy International Company, incorporated in the State of Delaware of the United States of America (hereinafter “El Paso”, “the Claimant”), filed a request for arbitration against the Republic of Argentine (hereinafter “the Government”, “Argentina” or “the Respondent”) with the International Centre for Settlement of Investment Disputes (hereinafter “the Centre” or “ICSID”). The Claimant alleges that Argentina has violated the 1991 Treaty Concerning the Reciprocal Encouragement and Protection of Investment between the Argentine Republic and the United States of America (hereinafter “the BIT”; bilateral investment treaties in general will be referred to as BITs), other rules of international law, the Hydrocarbon Concessions and Contracts as well as the Argentine Constitution.