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London

Founded in 2012, Signature Litigation has grown into one of London’s pre-eminent specialist dispute resolution practices. From the outset, we set out to do things differently: a conflict-free, disputes-only platform designed to give clients the undivided focus and strategic agility that complex, high-stakes matters demand.

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Gibraltar

Established in 2017, Signature Litigation's Gibraltar office was founded to address growing demand for specialist expertise in commercial litigation and private wealth disputes on the Rock.

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Paris

Signature Litigation AARPI houses one of France’s most enviable product liability practices, with the team also handling commercial and corporate litigation, insurance and reinsurance, toxic tort and ESG, civil fraud and asset tracing, international arbitration, administrative and public law.

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Frankfurt

Frankfurt has emerged as one of Europe's foremost financial and commercial centres and, increasingly, as a bridge between European and Asian markets. With that growth comes an increasing demand for sophisticated dispute resolution. Signature Litigation established its Frankfurt office to meet this need, bringing our conflict-free, disputes-only platform to the German market.

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Latin America

“The team is well versed in multiparty and cross-border disputes”
Chambers UK 2026, International Arbitration: Commercial Arbitration

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At Signature, our deep ties to Latin America – combined with a proven track record in many of the region’s most significant disputes – position us uniquely to advise clients operating or investing in the region.

We have handled disputes across the region and have distinctive strength and depth in matters involving Brazil. Our Lusophone desk is unique in the London market.

We are experienced in advising clients from and involved in the region across the full range of disputes practice areas covering cross-border civil litigation, asset tracing and recovery, international arbitration, investigations, and white-collar crime. Our work spans a broad range of industries, including infrastructure, mining, oil and gas, financial services, technology, telecommunications, commodities, pharmaceuticals, and retail.

Our approach is sector-agnostic and tailored specifically to the needs of our clients. Our trilingual team brings not only fluency in Portuguese, Spanish, and English, but also cultural eloquence and first-hand, on-the-ground experience across the region. We work closely with a trusted network of independent local professionals and leverage strong regional knowledge to navigate the legal, regulatory, and commercial landscapes of Latin America with confidence and agility.

We do not treat Latin America as a uniform market. Instead, we recognise the distinctive legal systems, business environments, and political contexts of each country. This allows us to deliver tailored, strategic solutions that reflect both global standards and local realities—always aligned with our clients’ commercial goals. We are experienced in engaging with local legal institutions, advising clients through regulatory and governmental interactions, and managing cross-border cases efficiently and effectively.

Brazil 

The depth of our capabilities and experience in Brazil and Lusophone jurisdictions stands alone in the London market. Members of our team are Brazilian-born, fluent in Portuguese, and/or have spent time living and working in the jurisdiction on major international cases. Our bilingual team is uniquely well-placed to advise clients on their most sensitive matters. Our Lusophone desk can receive instructions from clients and provide advice in Portuguese if preferred. We regularly work with Brazilian colleagues in advising clients on matters with an international dimension but also involving MPF, CADE, CGU and TCU amongst others.


Partner Ioannis Alexopoulos has over 30 years’ litigation and international arbitration experience which includes disputes in Latin America. He has particularly experience in Brazil and he speaks Portuguese. He specialises in financial services, energy/oil & gas, shipping/ international trade, telecoms, IT, and infrastructure projects. Ranked in The Legal 500 UK 2026 Guide’s ‘Hall of Fame’ and in the Chambers UK 2026 Guide for international arbitration, Ioannis is known for being “calm, but fast and decisive in actions” and “a great team leader and a wonderful person”.

Partner Mark Beardsworth has a 25-year track record of successful representations of individuals and corporates in major investigations. He has significant experience in conducting corporate internal investigations for clients that operate across a range of industries. He advises corporates on governance, compliance, management systems and controls, as well as on implementing policies. Mark has been ranked in the leading legal directories for white collar crime for over 15 years. He is a recognised expert for both individuals and corporates and is Band 1 ranked in the Chambers UK 2026 Guide for Financial Crime: Individuals, where he is described as an “excellent lawyer with a proven track record of successfully managing international cases across multiple jurisdictions”.

Partner Duncan Grieve has deep experience in leading cross-border investigations involving issues in foreign jurisdictions, acting for corporates, boards, and individual clients, and has advised on many of the major multinational cases of the last 15 years. He has leading experience in Brazil, Portugal, and Lusophone Africa. Duncan was listed in Global Investigations Review’s “40 under 40” in 2024 and is ranked in The Legal 500 UK 2025 Guide for Regulatory Investigations and Corporate Crime. He is known in the market for having “unparalleled experience in managing simultaneous enforcement actions by multiple international regulators and achieving successful outcomes for his clients,” and he is further described as an “astute tactician”, and “a star”.

Partner Catherine Naylor has nearly 20 years of experience supporting clients to resolve a broad range of commercial disputes, both domestic and cross-border, in particular offshore litigation. Catherine is ranked in The Legal 500 UK 2026 Guide as a ‘Next Generation Partner’ for commercial litigation, where she is commended for her expertise in multi-jurisdictional disputes. Clients describe her as “a highly able partner who can take control of the room and lead a team effortlessly through a case”, and praise her as a “stand out partner”, who is “cool, calm and collected, totally unflappable, and an absolute delight to work with.”

Counsel Pietro Grassi has a decade of experience in matters of public international law, investor-State arbitration, international commercial arbitration, business and human rights, and white-collar crime investigations in Latin America. He is a Brazilian qualified lawyer and a native speaker of Portuguese. Pietro is recognised as a ‘Leading Associate’ for international arbitration in The Legal 500 UK 2025 Guide, where he is described as “standout” and “extremely talented”. Previous Guides have also called him “excellent”, highlighting his “fantastic drafting skills” and “eye to the bigger strategic picture.”

"Hermès Marangos of Signature Litigation demonstrates considerable expertise handling complex insurance disputes spanning Latin American markets such as Chile and Mexico."

- Chambers Latin America 2025

Case Highlights

Advising a major international manufacturing company during a cross-border investigation involving the Serious Fraud Office, the U. S. Department of Justice and the Brazilian Ministério Público Federal.

Conducting an internal investigation into corruption allegations involving relationships between a Brazilian mining and commodities company and municipal and state government authorities in the North and Northeast of Brazil. The investigation occurred in the context of a USD 500m international investment into the Brazilian mining sector.

Conducting detailed assessments of corruption risk and whistleblower allegations in the context of a major international investment into a Brazilian multinational’s mining operation in Northern Mozambique.

Representing multinational and Brazilian corporate clients from the construction and infrastructure sector throughout the multifaceted investigations stemming from “Car Wash”. This work includes defence advice and advocacy facing the Brazilian prosecuting authorities and regulatory agencies, the negotiation of novel corporate leniency agreements, internal investigations and compliance remediation projects.

Leading numerous internal investigations and risk assessments, including in Brazil, Mexico and Argentina, as part of the global compliance integration of newly acquired company purchased for USD 5.1bn by a NASDAQ-listed conglomerate.

Advising a major Brazilian concessionaire through a Multilateral Development Bank investigation into alleged bribery involving a significant highway construction project in Brazil. We successfully represented the company throughout the investigation, appeal and sanction processes which resulted in our client obtaining co-operation credit and avoiding cross-debarment.

Instructed as part of the DOJ appointed independent monitorship team of a Brazil-headquartered international conglomerate operating in engineering, infrastructure, and petrochemicals sectors. The monitorship was the first-ever joint monitorship between the U.S. Department of Justice and the Brazilian authorities following the largest global foreign bribery resolution in history. The team conducted site visits, interviews, evaluated ongoing compliance risk and remediation efforts, covering the full span of the company’s projects within Brazil, and internationally, in Angola, Argentina, Colombia, the Dominican Republic, Ecuador, Guatemala, Mexico, Mozambique, Panama, Peru, Portugal, the United States, the Dominican Republic and Venezuela.

Representing a LATAM HNW family and their offshore company in a GBP 80m claim in England against an investment management company in relation to an investment in real estate in the UK. The claim concerns allegations of breach of duty and fraud.

Representing an Uhigh-net-worth individual/client client and his family in relation to misappropriation and fraud claims with the total value of in excess of USD 600m against a Panamanian trust and its trustees for the recovery of the trust’s funds in two separate ICC arbitrations. This involved a global enforcement strategy, pre-emptive court applications for interim relief (including worldwide freezing orders, asset disclosure orders and information orders) in number of jurisdictions including Cyprus, BVI and Singapore.

Representing a minority shareholder as one of the Respondents in a USD 600m complex ICC arbitration dispute with an international gambling software company which arises out of a partnership agreement for a joint online gambling project. This involved complex interrelated cross border court proceedings, including applications for anti-anti-suit injunctions and related substantive proceedings in the English courts.

Representing and securing a landmark jurisdictional victory for a European logistics company in USD 250m UNCITRAL arbitration proceedings against a LATAM country in connection with economic measures targeting an investment in the country’s customs infrastructure. This case expanded the ability of investors to bring their related contractual claims against host states through investment treaty arbitration instead of national courts.

Representing the Republic of Ecuador in two separate major, and high-profile investor-state disputes with the total value of nearly USD 3bn commenced by two consortium partners claiming expropriation of their oil & gas concessions. Significant success was achieved including securing an award in a counterclaim for USD 100m for environmental harm – the only successful counterclaim to date in investment arbitration.

Representing one of South America’s largest industrial conglomerates in a USD 200m dispute against a mining corporate in relation to a large-scale gold mining JV.

Representing a European investor in two separate ICSID disputes with the total value of USD 400m against a LATAM country in relation to the largest industrial plants for the production of glass containers and concerning direct expropriation, as well as violations of FET and full protection and security standards.

Representing one of the largest privately owned US industrial conglomerates in a USD 400m dispute against a South American country in relation to the development, construction and operation of two fertiliser factories and concerning expropriation, violation of FET and full protection and security standards.

Representing a major European retail group in a USD 2.5bn claim against its South American JV partner concerning breaches of a shareholders’ agreement relating to the issues of control in their joint venture company.

Representing CA Brazil Investment S.A., a Brazilian subsidiary of Paper Excellence, a global leader in pulp, paper and wood products manufacturing in a much-publicised dispute worth over USD 3bn with Brazilian companies owned by prominent Brazillian businessmen. The dispute related to the acquisition of a commodity producer in Brazil. The dispute spanned 6 years, involved four arbitrations, including three ICC arbitrations, and multiple court proceedings in several jurisdictions. We played an instrumental role in securing a global settlement between the parties.

Representing a French company against Brazilian and Luxembourgian companies in an ICC arbitration arising from their joint venture operating a cement company in Brazil and the implementation of a purportedly non-approved cement export project to the U.S.

KEY TEAM

Ioannis is an efficient lawyer and a pleasure to work with.

– Chambers UK 2026, International Arbitration

An excellent lawyer with a proven track record of successfully managing international cases across multiple jurisdictions.

– Chambers UK 2026 Guide

Unparalleled experience in managing simultaneous enforcement actions by multiple international regulators and achieving successful outcomes for his clients.

– The Legal 500 UK 2025 Guide

Commended for her expertise in multi-jurisdictional disputes.

– The Legal 500 UK 2026 Guide

He is described as “standout” and “extremely talented”

– The Legal 500 UK 2025 Guide