León Cosgrove

Diego Pérez Ara

Civil and common law-trained, Diego Pérez Ara helps clients navigate the murky waters of complex international disputes. his practice involves international and domestic arbitration (under most major institutional rules) federal and state court litigation, and proceedings before government regulatory agencies..

Diego has represented foreign and domestic corporates and sovereigns before Venezuelan and U.S. courts and all major arbitral institutions. His dual qualification allows Diego to understand the cultural and legal differences between the various legal systems and to help clients in whatever forum they may find themselves.

Diego has over a decade of experience navigating domestic and international disputes from inception through trial. He has successfully defended and prosecuted contract, non-compete, copyright, trademark, business torts and related matters. He has also handled international disputes, with a focus on Latin America, in energy, real estate, infrastructure and other industries, and both for and against sovereign governments.

Prior to joining León Cosgrove LLP, Diego worked at a large international law firm in New York and clerked for the Honorable Kathleen M. Williams for the United States District Court in and for the Southern District of Florida. While attending BU Law School, Diego was a research assistant for international arbitrator William (“Rusty”) Park and a teaching assistant for the BU Law LLM writing program.

Previously, Diego worked as a litigation associate in a major Venezuelan law firm in Caracas, focusing on international litigation and administrative law. As a civil law-trained lawyer, Diego has appeared before the Constitutional and Political-Administrative Chambers of the Supreme Court of Justice in Venezuela and before Superior and Trial Courts in Civil, Commercial, Labor and Administrative matters.


Represented a major entertainment company in a federal copyright action in the Southern District of New York and the Central District of California.

Represented three separate Saudi Arabian entities in two ICC arbitrations against a Latin American OCTG supplier, with total claims exceeding US$100M.

Co-led internal investigation of global company in Latin America.

Represented a Jamaican oil & gas company in arbitration disputes over fuel supplies to power barges.

Represented the Government of Mongolia in defending enforcement of an UNCITRAL and Energy Charter Treaty arbitration award relating to uranium mining rights.

Represented an Oklahoma Coal Plant in an AAA arbitration involving a Point-To-Point Transmission Service Agreement.

Successfully represented global company in action to collect evidence for use in foreign proceedings under 28 U.S.C. § 1782.

Represented death row inmates in Florida and Mississippi in post-conviction proceedings.