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Siobhan Kahmann


CMS EU Law Office
Avenue des Nerviens 85
1040 Brussels
CMS Cameron McKenna Nabarro Olswang LLP
Cannon Place
78 Cannon Street
United Kingdom
CMS Cameron McKenna Nabarro Olswang LLP
Saltire Court
20 Castle Terrace
United Kingdom
Languages English, French

Siobhan has practised EU and UK competition law for over ten years in Brussels and the UK, in addition to counselling clients on state-aid/subsidy, regulatory - including telco reg, policy and trade matters. She is an Advocaat with the Brussels Bar, and a Solicitor in Scotland, England and Wales. Her competition experience has included: complex cartel infringement assessments, defence, and leniency applications; detailed vertical, horizontal, tech transfer and motor vehicle agreement analysis and support; substantial advice on different market inquiries; strategic and in-depth counsel for clients in abuse of dominance claims; and significant experience in matters on UK, European and international merger control. She also routinely advises on all aspects of state-aid and subsidy laws.

She has extensive experience advising on competition law in the tech industry, including IoT, big data and artificial intelligence, in addition to automotive and other transport, and on evolving sustainability and FMCG issues. Siobhan has recently spent over a year working as a senior in-house competition counsel at a global oil and gas company, where her focus included advising on new energies initiatives and electric car charging infrastructure, in addition to supporting a leading FMCG brand as its only in-house global senior competition counsel. She also specialises in different aspects of tech regulation, including telco reg, net neutrality, and autotech with broad experience in electric and autonomous vehicles. Siobhan is the Law Society of Scotland’s elected International Council Member and is an active member of its Competition Committee, Tech Committee and Trade Working Group.

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Relevant experience

  • Cartel defence: advising clients across different industries on cartel defence strategies and procedures in the EU and at national level including leniency applications, and all stages of investigations. 
  • E-commerce: engaging in comprehensive e-commerce review, training and strategy for clients in a number of different sectors and jurisdictions.
  • Agreements: providing detailed and practical legal advice and training to a diverse range of MNCs on vertical, horizontal and other complex arrangements.
  • Abuse of dominance: counselling clients on formulating abuse of dominance complaints including strategy and policy towards regulators and responses to investigations, in addition to defence approaches and official responses.
  • Compliance programmes: compiling extensive and tailored compliance programmes and training for various clients across numerous sectors and jurisdictions, including designing e-learning modules.
  • Merger control: strategically advising on and securing the clearance of a number of mergers, including but not limited to the automotive industry, at both national and European level.
  • State-aid/subsidy: providing strategic support and analysis on all types of state-aid and subsidy review and awards, and defending decisions on no award of aid.

Other Regulatory

  • Telco Reg: providing wide-ranging telco reg advice from both a UK and EU perspective, including electronic communications services rules and regulations, and relevant restrictions, obligations and opportunities applicable across the various frameworks and evolving service categories/aspects
  • Net Neutrality: advising on pan-European net-neutrality issues, with a focus on zero-rating.
  • EV: counselling clients in the evolving electric/autonomous vehicle and energy industry on a range of competition and regulatory issues, state-aid/subsidy and policy support.
  • Regulatory: providing legal support and analysis across a wide-range of EU regulatory and competition issues including sustainability, energy, emissions, CRS, free movement and environmental frameworks.
  • Trade: preparing trade submissions for a variety of different EU and WTO procedures.
  • Policy: supporting and enabling clients’ successful engagement on policy issues with the EU institutions.
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Memberships & Roles

  • Advocaat, Brussels Bar (Dutch)
  • Solicitor and Notary Public, Law Society of Scotland
  • Solicitor, Law Society of England and Wales
  • Writer of the Signet to her Majesty the Queen (WS)
  • Elected Council Member (International), Law Society of Scotland
  • Committee Member, Competition, Tech Law, and International Trade Committees, with the Law Society of Scotland
  • Observer Member in the EU Law Committee, Member of the Competition Section, Law Society of England and Wales
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Siobhan is a regular contributor and presenter on a range of legal developments including competition law, e-commerce, big data, net neutrality, technology law, and electric and autonomous vehicles. She has also written and presented extensively on Brexit, including on competition law, and lawyers’ practising rights.

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  • LL.B Honours, University of Aberdeen
  • LL.M, EU Competition and Business Law, Universiteit van Amsterdam
  • DLP, University of Edinburgh 
  • QLTT English Law, College of Law
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