Mercedes has been a Partner in Ontier’s Litigation and Arbitration Department since 2023, having previously held partnership positions at leading international and domestic law firms.
She has over 20 years of experience in high-value, complex judicial and arbitral proceedings, conducted in both English and Spanish, across sectors including energy and natural resources, construction, engineering and infrastructure, commercial litigation, shareholder disputes, and sports.
Her experience includes acting in both domestic and international arbitration proceedings administered by the International Chamber of Commerce (ICC), the London Court of International Arbitration (LCIA), the Madrid Court of Arbitration (CAM), the Madrid International Arbitration Center (CIAM), the Civil and Commercial Court of Arbitration (CIMA), and the Spanish Court of Arbitration (CEA). She also regularly acts as an arbitrator.
She is ranked by Chambers & Partners and Legal 500, listed among Spain’s top arbitrators by Leaders League, and was recognized as Best Arbitration Lawyer in the “40 under Forty” Awards.
Advising an energy company in an international gas arbitration under the LCIA Rules.
Advising a construction company in connection with a solar power plant in an international arbitration under the ICC Rules of Arbitration.
Representation of an energy company in litigation relating to gas and electricity distribution agreements.
