Constantin Rehaag

Practice Areas

Dr. iur. Constantin Rehaag, M.A., a renowned Intellectual Property (IP) and Technology expert, based in Baker McKenzie's Frankfurt office, leads the German IP team. Constantin Rehaag advises numerous national and international companies, particularly in the technology and digital economy, life sciences and pharmaceuticals, and luxury and consumer goods sectors.

He has more than 17 years of experience in intellectual property law. His IP litigation practice spans disputes in unfair competition, trademark, design, copyright, trade secret and patent law. A particular focus of his work lies in the cross-border enforcement of IP rights and strategic brand management. He also regularly advises on AI-driven business models. Another key area of his practice is combating product and brand piracy, including related criminal enforcement measures.

Leading legal directories recognise his outstanding expertise. He is recommended by Chambers, The Legal 500, JUVE, Best Lawyers and WTR 1000. He is a regular speaker at Eurojust and the German Judicial Academy and is a member of the Legal Expert Commission of the EUIPO Observatory.

Career

Partner, Baker McKenzie (Frankfurt), 2026-Present.

Partner, Dentons (Frankfurt), 2015-2026; prior roles include Counsel at Dentons/Salans and Associate at Mayer Brown.

Lecturer in law (University of Passau); faculty at the German Judicial Academy for advanced judicial/prosecutorial training; EUROJUST trainer for EU Member State prosecutors.

Certified specialist lawyer for intellectual property law (Fachanwalt für gewerblichen Rechtsschutz) and frequent conference speaker on litigation and trade secrets.

Professional Memberships

• Professional memberships include GRUR and the German-British Jurists’ Association.

• EUIPO Observatory Legal Expert Group (supports the European Commission; case law and studies on trade secrets, copyright, blocking orders, and broader IP topics).

Work Highlights

• E-commerce and competition success: Successfully represented the world’s largest e-commerce company in trademark and antitrust litigation up to the German Federal Court of Justice, demonstrating capacity to carry complex platform-related disputes through to the highest level.

• Major pharmaceutical enforcement: Advised a market-leading German and Swiss pharmaceutical companies in civil and criminal proceedings in the largest known case of illegal sales of pharmaceuticals in Germany, showcasing blended civil/criminal strategy and sector acuity.

• Patent disputes across industries: Represented a global market leader in tissue, a Swiss pharmaceutical company (Germany and Hungary), and a Polish glass manufacturer in patent infringement and invalidity proceedings, underscoring courtroom experience in technically complex cases.

Experience

• Trade secrets and crisis mandates: Implemented business secret programs for pharma and chemical clients; pursued civil and criminal proceedings to recover stolen business secrets (including against a former director of a German affiliate), and defended a pay-TV channel against brute force attempts targeting confidential information.

• IP protection for technology and AI-adjacent assets: Represented an American multinational technology company on IP litigation and protection of algorithms, aligning with emerging AI/IP protection strategies and confidentiality controls for high-value code and models.

• Brand and design enforcement: Enforced rights for toy and luxury/fashion clients; advised on design registration and subsequent enforcement for MFP manufacturers, reflecting a cradle-to-court approach to product IP.

• Cross-media and content matters: Defended a world-leading printing press manufacturer in a copyright claim and advised a music industry client on securitisation of a major portfolio in Germany, bridging IP with financing and media.

Education