LAWYER PROFILE
Antonio Vázquez-Guillén

Antonio Vázquez-Guillén

Global 2026

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Ranked in 2 practice areas

About

Provided by A&O Shearman

Practice Areas

Arbitration, Dispute Resolution and Energy & Natural Resources

Personal

Antonio is Global Co-Head of Litigation & Investigations and Co-Managing Partner of Spain. He established the Madrid Litigation and Arbitration department in 2008 and has grown to an international team of over 25 lawyers from six different nationalities.

Antonio has led many complex civil litigation proceedings representing major corporates and financial institutions, particularly regarding the enforcement of financial guarantees, as well as in a wide variety of high profile commercial arbitration proceedings under the ICC, Madrid Chamber of Commerce and CIMA arbitration rules, representing both Spanish and foreign entities, including among others disputes pertaining to price reviews, infrastructure projects, representations and warranties or shareholder agreements.

Antonio also routinely advises companies as regards potential investment treaty disputes against foreign States regarding their oversees investments. From 2011, Antonio designed the strategy, together with the firm's London office, to initiate an investment-treaty arbitration under the ECT against the Kingdom of Spain on behalf of 14 groups of international investors that invested in the Spanish renewable energy sector. This was the first-ever collective claim brought under the ECT. To date, Antonio has acted for investors of six different nationalities in 12 different cases against the Kingdom of Spain.

Prior to joining the firm in 2005, Antonio served as a State Lawyer for eight years, representing the Spanish State in various high-profile civil, administrative and criminal cases. Antonio notably handled the civil and criminal liability proceedings arising out of MV Prestige oil spill, the worst ecological disaster in the history of the Iberian peninsula and one of the worst of Europe. Antonio also pursued claims before the International Oil Pollution Compensation (IOPC) Fund in London and the American Bureau of Shipping in New York.

Antonio is a well-known and reputed lawyer in the Spanish market, routinely advising the general counsels of the main corporates and financial institutions present in the Spanish market on strategic litigation matters key to the businesses they are responsible for.

Antonio also regularly acts as arbitrator in cases under the ICC or CIMA rules.

He has been recognized as Best Lawyer in Spain by Expansión (Spanish Financial Times) for his outstanding profile and reputation in the country.

Chambers Review

Provided by Chambers

Chambers Global Guide

Litigation: Elite - Spain

Band 1
Band 1

Individual Editorial

Market-leading partner Antonio Vazquez-Guillén retains his top-tier ranking after eliciting ample market praise. He is well placed to represent clients from the infrastructure, real estate and energy sectors in civil and commercial disputes.

Energy & Natural Resources - Spain

Band 4
Band 4

Individual Editorial

Antonio Vazquez-Guillén acts for energy corporations and investors on high-profile contentious international and domestic mandates. He also assists with regulatory matters.

Strengths

Provided by Chambers

  • Antonio is a highly qualified professional with extensive experience in various sectors and the global vision to understand the needs of the client.

    Litigation: EliteChambers Global Guide

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