US Supreme Court appeal deadline expires in YPF lawsuit

The 30-day extension granted by the US Supreme Court for plaintiffs to file their final appeal over the renationalisation of YPF expired on Wednesday, September 30, 2026. In August, the court postponed the original August 31 deadline for the petition for a writ of certiorari, marking the final possible stage of the long-running US litigation.

The appeal follows a decision in March by the US Court of Appeals for the Second Circuit in New York, which completely reversed a September 2023 ruling issued by District Judge Loretta Preska. That lower-court ruling found the Argentine State breached YPF's bylaws and ordered it to pay $16.1 billion, consisting of $14.4 billion to Grupo Petersen and $1.7 billion to Eton Park. With accumulated interest, the total claim approached $18.0 billion before being dismissed, an outcome President Javier Milei described as the best possible scenario. In June, the appellate court also rejected a request to reconsider its ruling.

The Supreme Court in Washington receives between 7,000 and 8,000 certiorari petitions each year and agrees to hear roughly 100. Filing the request is procedural and does not obligate the justices to take the case.

In parallel, litigation funder Burford Capital initiated arbitration against Argentina before the World Bank's International Centre for Settlement of Investment Disputes (ICSID) in Washington. The claim invokes a 1991 bilateral investment treaty between Argentina and Spain, triggering a 90-day tribunal formation phase for a confidential process that could take five to 10 years. Argentina's Treasury Attorney General's Office confirmed receipt of the notification, facing an ICSID track record where 85% of rulings have gone against the country.