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Thomas Sonnenberg

Dr. Thomas Sonnenberg


CMS Hasche Sigle
Kranhaus 1
Im Zollhafen 18
50678 Cologne
Languages German, English, French

As a highly regarded expert on international corporate structures, Thomas Sonnenberg specialises in the field of strategic compliance and corporate governance. His practice also covers corporate and stock corporation law, M&A and private equity transactions as well as finance, banking and related regulatory matters.

Before joining CMS, Thomas had been at private bank Sal. Oppenheim for almost 20 years, eight of which as general counsel. He subsequently joined industrial services provider Ferrostaal as general counsel in 2010, followed by general counsel, chief compliance officer and head of the management and supervisory board office positions at construction group Hochtief in Essen. Thomas then worked for private equity investor Triton as general counsel and head of corporate governance before joining CMS in 2016.

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Relevant experience

  • Advising an international conglomerate in the consummation of internal investigations
  • Advising on the group-wide introduction of monitoring and control processes in connection with the combat of bogus employment and improper hiring-out of employees
  • Advising a medium-sized business in connection with reorganization of internal export control
  • Advising several businesses on anti-money laundering organization, in particular for distribution activities in Eastern Europe
  • Advising the buyer on the acquisition of the private equity fund-of-fund business of a major German bank
  • Advising an international mechanical engineering group on intra-group mergers
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  • 1992: Second state examination in law, Cologne
  • 1989: PhD (Dr. iur. utr.), University of Cologne
  • 1987: First state examination in law, University of Cologne
  • 1982 - 1987: Law studies at the University of Cologne
  • 1980 - 1982: Apprenticeship in banking
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  • „Kommunikation als Schlüssel zu erfolgreichem Compliance-Management – Sieben Thesen“, Compliance-Berater 2019, 1 (Co-authors: Christina Ritzenhoff, Prof. Dr. Martin Schulz), („Communication as a key for successful compliance management – seven thoughts“)
  • „Non-compliance in China – Obligations and Risks for German Employees, German Parent Companies and their Management”, in: Senff/Zhang, “Governance, Risk and Compliance Management in China”, 2018
  • „Compliance-Systeme in Unternehmen”, JuS 2017, 917 („Compliance-systems in commercial businesses“)
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