Guilherme Santos Silva

Partner | Lisbon

Guilherme Santos Silva is a Partner at Abreu Advogados since 2004, working primarily on matters related to civil, commercial and transportation litigation matters, as well as on domestic and international arbitrations, for more than 28 years.

Guilherme is co-coordinator of the Litigation and Arbitration practice area at Abreu Advogados. He works in civil and commercial litigation and arbitration, with an emphasis on complex international and multi-jurisdictional proceedings.

In this area, he has a vast experience in international litigation and arbitration, having assisted and represented clients in cases involving multiple jurisdictions, such as Angola, United Kingdom, Saudi Arabia, China, Switzerland, France, Israel, Brazil, Mozambique, Germany and the Netherlands, besides Portugal.

Guilherme Santos Silva is also co-coordinator of the Angolan Desk of Abreu Advogados, having worked actively in matters related to Angola for more than 20 years, assisting foreign companies with interests in that country in the Energy (Oil & Gas and Electricity), Telecommunications, Aviation and Maritime, Natural Resources, Real Estate and Construction, Compliance and Regulatory, as well as foreign investment, commercial and corporate law and dispute resolution sectors.

He also assists Angolan companies operating abroad, as well as in matters in other Portuguese-speaking African countries, having in-depth knowledge of the law in a wide range of sectors. Guilherme has also had several cases in Portugal relating to construction, sale, mortgage, seizure and attachment of ships and aircraft and related contractual matters, having assisted clients of various nationalities in the respective proceedings.

He was an Assistant Professor at the Moderna University of Lisbon from 1993 to 2007. Guilherme is the author and co-author of several articles and works on matters related to his practice, published by national and international publishers, including Wolters Kluwer, Martinus Nijhoff (Brill) Publishers and Yorkhill Law Publishing. More recently, he wrote the chapter dedicated to “Recognition and Enforcement of Foreign Arbitral Awards” of the work “International Arbitration” in Portugal (Kluwer Law) and contributed to the chapters dedicated to Portugal of “Force Majeure” (Brill-Nijhoff) and “Enforcement of Foreign Judgements” (Kluwer Law).

He contributed to the Portuguese chapter and its update of the “New York Convention Guide” ( In 2022 he co-authored the first “Arbitration, Conciliation and Mediation Law of Mozambique Commented”.

He also frequently participates in national and international conferences and seminars on litigation and arbitration, where he has also been a speaker.

Arbitration and Mediation, Portugal (2020-2022)

Corporate Law, Portugal (2020-2022)

Litigation Law, Portugal (2020-2022)

Transportation Law, Portugal (2010-2022)

Guilherme Santos Silva acts on maritime law cases as part of a wider practice which spans dispute resolution and financing issues.

Guilherme Santos Silva co-leads the team and offers advice to large international corporations on high-value, multi-jurisdictional litigation matters. His expertise encompasses civil and commercial disputes.

Band 4, Dispute Resolution “Guilherme Santos Silva comes recommended by sources, who state that his “advocacy and thinking on his feet are top-class.” He represents clients in commercial and civil litigation as well as transportation litigation, frequently acting for clients in regulated sectors.”

Band 4, Dispute Resolution “Peers note Guilherme Santos Silva’s experience in ship registration and mortgage enforcement mandates. He also acts for insurers on commercial litigation relating to contracts of carriage.”

Best Lawyer of the year – Transportation Law (2016)


Advising a multinational Client in an international dispute with several Angolan parties involving an ICC arbitration in Paris (the Arbitral Tribunal ordered the other parties to pay the Client an amount in excess of USD 650 million), as well as Court proceedings in several countries, including Angola, France, BVI and the Netherlands.

Advising in an International dispute regarding an 800 million USD contract in the sphere of solar energy, involving an ICC arbitration in Geneva, as well as Court proceedings in Portugal and China.

Advising an UK Bank in an international dispute regarding a 400 million EUR contract in the Media sector, involving several Court proceedings in Portugal.

Advising a Spanish Energy company in an arbitration in Portugal against a Portuguese energy company.

Advising a Shipyard in a dispute in excess of 40 million EUR, involving several Court proceedings and an arbitration in Portugal.

Advising a Venture Capital Fund in an arbitration in Portugal against several entities.

Advising an Angolan independent power producer in an Ad-hoc Uncitral arbitration (Lisbon) against an Angola’s state Company.

Advising a Swiss Client in a dispute against an American company involving Court proceedings in Portugal and UK.

Advising a Portuguese company in LCIA arbitration (London) proceedings filed by a foreign company.

Advising an International Client in the EPC contract for the Angola LNG.

Advising Angola LNG consortium in several matters regarding the Angola LNG project.

Advising a Brazilian Client with the sale (1 billion USD) of a Portuguese subsidiary with interests in Angola.

Advising an Israeli Client in Court proceedings in Portugal involving the wet lease of an aircraft.

Advising an Australian shipyard on an international public tender for the construction of ferries and subsequent Court proceedings regarding the tender.

Advising an Angolan state company in Court proceedings in Portugal filed by a Portuguese company.

Advising an Angolan Client regarding a multimillion USD contract and an arbitration in Russia.

Advising an international Client with the purchase of a participation in an off-shore deep water wind farm



Faculdade de Direito da Universidade Católica Portuguesa

Law degree (1991)