LAWYER PROFILE

Guillermina Ester

Europe 2026

Pérez-Llorca

Ranked in 1 practice area

Litigation: Elite

Spain

2 years ranked

About

Provided by Pérez-Llorca

Europe

Practice Areas

Litigation & Arbitration, Civil/Commercial/Corporate Litigation, Contractual Disputes (joint ventures, SPAs, distribution, construction & EPC, price adjustments), Corporate Litigation (directors’ liability, shareholder disputes), Unfair Competition, Banking Litigation.

She acts in complex pre-litigation and litigation before all tiers of the Spanish courts and in domestic and international arbitrations.

Career

Guillermina is a partner (since 2010) in Pérez-Llorca’s Litigation & Arbitration practice. She represents Spanish and international clients in high-value civil, commercial and corporate disputes and arbitrations, including urgent interim relief and multi-party matters.

- 2018 General Management Programme (PDG), IESE Business School

- 1999 Degree in Law, Universidad Carlos III de Madrid

- 1997 International Law Programme, Law Faculty of Universitat van Amsterdam

She works in Spanish and English.

Professional Memberships

Madrid Bar Association (ICAM).

Spanish Arbitration Club (CEA) and CEA under 40.

Website Officer of the Litigation Committee of the International Bar Association (IBA).

Chambers Review

Provided by Chambers

Chambers European Guide

Litigation: Elite - Spain

Band 2

Individual Editorial

Guillermina Ester regularly advises clients on contractual, competition and shareholder disputes. She also handles disputes at the ECJ.

Learn more about this team View ranking table

Strengths

Provided by Chambers

Guillermina has a spectacular strategic outlook, knowing how to combine technical knowledge with complex situations.
Litigation: EliteChambers European Guide
Guillermina is an excellent professional with technical preparation and a great customer orientation. She provides a clear view of business and legal risks and recommends the best alternatives.
Litigation: EliteChambers European Guide
Guillermina is reliable and a strong contributor to the team’s overall performance.
Litigation: EliteChambers European Guide
She offers great solidity, capacity for effort and attention to detail.
Litigation: EliteChambers European Guide