Repsol required to buy Eskenazi family YPF stake The accord includes an obligation for Repsol, under certain conditions, to take over loans the family used to buy YPF shares. Repsol, based in Madrid, would probably try to fight a move by the Eskenazis to enforce the accord by using a so-called force majeure argument, according to two lawyers familiar with the matter who saw the agreement or were briefed on it. Repsol would argue that Argentina's seizure of 51pc of its YPF oil company was an unforeseeable event that prevents it from fulfilling its obligation to the Eskenazis, said Tom Ginsburg, a professor of international law at the University of Chicago, in a telephone interview. He hasn't seen the accord. Repsol Chairman Antonio Brufau this week estimated the company's potential loss at €5.7bn for the Argentine government expropriating most of Repsol's stake in YPF. A Repsol spokesmen in Madrid declined to comment. Repsol's American depositary receipts fell 3.5pc to close at $19.33, their lowest since June 2010. Brufau has said Argentina's nationalization of the oil company, which had a market value of about $16 billion in January, was illegal. A spokesman for the Eskenazis" Petersen Group holding company, which owns about 25pc of YPF, didn't respond to phone calls and e-mails seeking comment. Repsol fell 16pc in the past three days in the Spanish stock market. Its debt rating yesterday was cut one level by Standard Poor's Ratings Service to the lowest investment-grade level. Argentina President Cristina Fernandez de Kirchner ousted Sebastian Eskenazi as the head of Buenos Aires-based YPF on April 16, appointing Planning Minister Julio de Vido and Deputy Economy Minister Axel Kicillof to run the company and announcing plans to seize a 51pc stake in YPF from Repsol. The takeover follows those of airline Aerolineas Argentinas SA and a $24 billion pension fund by Fernandez since she took office in 2007. The Eskenazis made their fortune in banking and construction, buying 15pc of YPF from Repsol in 2008 in a deal backed by then-president Nestor Kirchner, the late husband of Fernandez. The acquisition was financed with a syndicated bank loan and a seller's note from Repsol. The Eskenazis bought an additional 10pc of YPF in 2011 with two similar loans.