Marval O’Farrell Mairal

Labor & Employment

He is part of the litigation team specializing in complex employment lawsuits that manages a portfolio of high-profile lawsuits, primarily disputes with executives, directors, and expatriates. Over the past decade, the team has defended multinational companies in a portfolio valued at over USD 600 million, including Argentina's most economically relevant individual labor law trial. He also provides advice from the labor perspective on mergers, due diligences, complex compensation structures, hires, and sensitive and massive terminations. At the same time, he is a member of the Firm's Strategic Innovation Committee, which has developed various technological solutions for the management of claims and lawsuits.

Guillermo M. Osorio joined Marval in 2009, and he has been a partner of the Labor Department since 2019.

Spanish - English - Portuguese

He is a member of the City of Buenos Aires Bar Association and the San Isidro Bar Association.

Guillermo graduated from Universidad de Buenos Aires with a law degree in 2007. Afterwards, he completed multiple postgraduate degree courses at the Pontifical Catholic University of Argentina  (Specialization in Labor Law) and Torcuato Di Tella University (Complex Litigation and Labor Complex Litigation before the Supreme Court of Justice). He also completed multiple continuing education courses at Asociacion Argentina de Derecho del Trabajo y la Seguridad Social. And in September 2020, he completed the Harvard University’s CS50 for Lawyers course. In addition, he taught courses on strategic planning for labor trials at the San Isidro Bar Association.He is a member of the City of Buenos Aires Bar Association and the San Isidro Bar Association.