Guillaume Guérin

Counsel, Paris

Guillaume Guérin

Counsel, Paris

Guillaume Guérin, Counsel au sein du bureau de Paris, conseille des sociétés cotées ou non-cotées et leurs dirigeants, des fonds d’investissement, et des institutions financières, tant en conseil (regulatory, compliance et opérations de marché) qu’en contentieux.

Guillaume a une expérience significative dans le cadre de procédures d’enquête, de contrôle et de sanction auprès de l’Autorité des marchés financiers (AMF) et de l’Autorité de contrôle prudentiel et de résolution (ACPR), ainsi que dans le cadre de procédures de coopération internationale avec d’autres autorités de régulation (SEC), et le cas échéant, leurs suites judiciaires.

Guillaume a une expérience étendue dans le cadre d’opérations de cession ou d’acquisition de sociétés cotées ou non cotées, d’opérations de marché (offres publiques, retrait de la cote…), et de levée de fonds (introductions en bourse, émissions de titres, ICOs), ainsi qu’en matière de gouvernance d’entreprise et de communication financière.

Guillaume est reconnu par The Legal 500 dans la catégorie stock market litigation en France. Guillaume a également été reconnu par Leaders League dans la catégorie “Highly Recommended” pour la compliance en France.

Guillaume a débuté sa carrière à l’AMF où il a travaillé cinq ans à la direction des enquêtes puis à la direction des affaires juridiques. Avant de rejoindre le cabinet, il a été collaborateur du bureau de Paris de Salans devenu Dentons, puis de DLA Piper.

Guillaume est aussi administrateur de l’Association des Avocats en Droit Boursier (ADB).

Guillaume est titulaire d’un LL.M. de l’Université de Virginia School of Law et d’un DJCE-DESS en droit des affaires et fiscalité de l’Université Jean Moulin Lyon III.

Guillaume Guérin, Counsel au sein du bureau de Paris, conseille des sociétés cotées ou non-cotées et leurs dirigeants, des fonds d’investissement, et des institutions…

Five of our Paris-based lawyers have been recognized in the 2025 edition of The Best Lawyers in France.

Johannes Jonas is recognized for corporate law. His practice focuses on cross-border transactions and investments, mergers and acquisitions, employment law, and general commercial law.

Angéline Duffour is recognized for labor and employment law. Her practice focuses on all aspects of employment law in a diverse range of industries (including hospitality and leisure, life sciences and health care, chemical industries, luxury, fashion and transportation).

Muriel Goldberg-Darmon is recognized for banking and finance law, financial institutions, mergers and acquisitions law, and regulatory practice. Her practice focuses on advising listed companies and their managers, investment funds, insurance companies, and financial institutions on a wide range of regulatory and compliance issues, investigations, and corporate transactions.

Franck Le Mentec is recognized for tax law. His practice focuses on cross-border taxation, both for multinational enterprises and private clients.

Guillaume Guérin is recognized for regulatory practice. His practice focuses on advising publicly listed and non-listed companies and their managers, investment funds, and financial institutions on a wide range of regulatory and compliance issues, investigations, and corporate transactions.

The Best Lawyers in France relies entirely on peer review to determine and recognize professional excellence.

Established in 2014, Cohen & Gresser’s Paris office provides comprehensive legal services for our clients, including advising on corporate, employment, tax, financial services, white collar defense, and litigation-related matters. Our Paris attorneys work closely with the lawyers in our other offices on cross-border transactions, investigations, and litigation, in order to provide superior service to French and international clients.

Cohen & Gresser is pleased to share that The Legal 500 Europe, Middle East and Africa (EMEA) 2024 edition has recognized the firm’s Paris office for excellence in Stock Market LitigationEmployment and Tax.

Partner Franck Le Mentec is one of only four lawyers in France recognized as a Leading Individual in Transfer Pricing and International Tax, and partner Muriel Goldberg-Darmon is one of only 16 lawyers in France recognized as a Leading Individual for Stock Market Litigation, encompassing AMF investigations and sanction proceedings.

The 2024 edition also recognized partner Angéline Duffour as a recommended lawyer for Employment, and counsel Guillaume Guérin as a recommended lawyer for Stock Market Litigation.

Established in 2014, Cohen & Gresser’s Paris office provides comprehensive legal services on corporate, employment, tax, financial services, white-collar defense, and litigation-related matters. Our Paris lawyers work closely with the lawyers in our U.S. and UK offices on cross-border transactions, investigations, and litigation, providing superior service to our French and international clients.

The Legal 500 EMEA guide provides annual researched coverage of over 80 countries and over 2,700 law firms. The research involves a detailed assessment of various factors, including work conducted by law firms over the past 12 months and historically, experience and depth of teams, and client feedback.

Cohen & Gresser is pleased to share that The Legal 500 Europe, Middle East & Africa (EMEA) has recognized the firm’s Paris office for excellence in Stock Market Litigation, Employment and Tax in its 2023 edition. Paris partner Muriel Goldberg-Darmon is one of only 17 attorneys in France designated as a Leading Individual for Stock Market Litigation (including AMF investigations and sanction proceedings), and Paris partner Franck Le Mentec is one of only 4 attorneys in France designated as a Leading Individual in Transfer Pricing & International Tax.

The 2023 edition also recognized Paris partner Loïc Henriot and counsel Guillaume Guérin as recommended lawyers for Stock Market Litigation, and partner Angéline Duffour and counsel Anna Milleret-Godet as recommended lawyers for Employment.

Established in 2014, Cohen & Gresser’s Paris office provides comprehensive legal services on corporate, employment, tax, financial services, white-collar defense, and litigation-related matters. Our 14 Paris attorneys work closely with the lawyers in our other offices on cross-border transactions, investigations, and litigation, in order to provide superior service to French and international clients.

The Legal 500 EMEA guide provides annual researched coverage of over 80 countries and over 2,700 law firms. The research involves a detailed assessment of various factors including work conducted by law firms over the past 12 months and historically; experience and depth of teams; and client feedback. These latest Legal 500 recognitions for nearly half our Paris office are a testament to the firm’s extensive capabilities in the international arena.

Cohen & Gresser’s Paris office has earned six practice rankings and 13 individual rankings in the 2022 Leaders League guide. Leaders League highlights the firm’s “experienced lawyers” and ability to handle complex, cross-border matters.

Leaders League is an independent research and rating agency that provides comprehensive rankings and in-depth analysis of law firms and lawyers. The rankings are based on extensive research by an experienced team of analysts.

Ranked Practice Areas:

• Marketing, communication & digital – Advertising law & marketing

• Media & entertainment – Fashion Law

Ranked Individuals:

Franck Le Mentec: Wealth management – Wealth tax: regulation and litigation; Tax law – LBO tax

Guillaume Guérin: Compliance – Compliance program

Johannes Jonas: Private Equity – Development capital transactions

Loïc Henriot: Dispute resolution – Litigation with regulators and for listed operations; Compliance – Compliance program; Compliance – International investigation and internal investigation; Dispute resolution – Banking & Finance Litigation; Dispute resolution – Commercial litigation; Labor & Employment – Criminal labor law; Dispute resolution – White collar crime

Muriel Goldberg-Darmon: Dispute resolution – Litigation with regulators and for listed operations; Compliance – Compliance program; Compliance – International investigation and internal investigation; Private Equity – Development capital transactions; Asset management – Asset management

Established in 2014, Cohen & Gresser’s Paris office provides comprehensive legal services for our clients, including advising on corporate, employment, tax, financial services, white collar defense, and litigation-related matters. Our Paris attorneys work closely with the lawyers in our other offices on cross-border transactions, investigations, and litigation, in order to provide superior service to French and international clients.

International law firm Cohen & Gresser is pleased to announce that its Paris office has once again been recognized in The Legal 500’s 2022 Europe, Middle East, and Africa (EMEA) guide for its work in five practice areas: Commercial Litigation, Employment, IT and Internet, Stock Market Litigation, and Tax. The Legal 500 recognizes practices that are “providing the most cutting edge and innovative advice to corporate counsel.” Clients recognized C&G for its “ability to synthesise, analyse and argue matters” and noted that the firm “has an extensive technical track record and is able to support French and foreign clients” on all types of issues. Two C&G lawyers received top-level rankings and have been recognized as “Leading Individuals” in their respective practice areas. The full list of C&G lawyers recognized in The Legal 500 2022 EMEA guide includes:  

Guillaume Guérin was featured in an article by Agefi-Dow Jones in which he discusses Vallourec’s (a multinational manufacturing company) contemplated share capital reduction and consolidation of shares.

Cohen & Gresser announces the expansion of its White Collar Defense & Regulation team in Paris. Partner Muriel Goldberg-Darmon and Guillaume Guérin will advise listed companies and their managers, investment funds, insurance companies, and financial institutions on a wide range of regulatory and compliance issues, investigations, and corporate transactions.
Dans cet article pour Finascope, Muriel Goldberg-Darmon, Guillaume Guérin, et Pierre Wolman analysent le communiqué du 29 mai 2024 publié par l'Autorité Européenne des Marchés Financiers (ESMA) concernant les bonnes pratiques à suivre par les sociétés cotées dans le cadre de leurs échanges avec les analystes financiers avant la publication des résultats financiers. Ils évoquent en outre la position de l'AMF sur le sujet.

Dans cet article pour Finascope, Muriel Goldberg-Darmon, Guillaume Guérin, et Pierre Wolman analysent une proposition de loi visant à introduire la possibilité pour les sociétés cotées d’émettre des actions à droits de vote multiples au moment de leurs cotations. Ils évoquent notamment le régime de ces actions et l’impact que cette proposition de loi pourrait avoir sur l’attractivité de la place de Paris.