Jacquelyn MacLennan

Partner, Brussels, London


“A superb practitioner and very good public speaker who always looks for solutions.”
Chambers Europe 2015


Jacquelyn MacLennan offers a wealth of experience for clients worldwide, representing leading multinational corporations, governments and trade associations.

She focuses on EU competition law, and clients benefit from her experience and insight in developing strategy and running major international cartel investigations, as well as advising on complex distribution problems and licensing arrangements, abuse of dominance cases, mergers and joint ventures.

Jacquelyn is a core team member of the firm's Business & Human Rights Interest Group and advises on a wide range of issues related to ESG and sustainability, including corporate supply chain compliance, disclosure requirements, and Business & Human Rights issues generally.

She also advises on EU customs and trade law, international sanctions, and EU regulatory requirements, notably in respect to product safety and environmental regulation.   

With an impressive track record of experience and know-how, Jacquelyn litigates regularly before the EU and UK courts, and represents clients before the European Commission.

Jacquelyn has accumulated substantial management experience over her career; she has been a Member of the Partnership Committee (the main governance body) of White & Case, a Member of the Executive Committee (responsible for the firm's strategy), and Executive Partner heading the Brussels office. In October 2015, she became the Global Pro Bono Practice Leader.

Clients describe Jacquelyn as "excellent – an industry leader in antitrust matters" and "commercially-minded and solution-oriented." (Chambers Europe, 2016)

Bars and Courts
Solicitor in Scotland
Notary Public
Brussels Bar
Diploma in Legal Practice
University of Edinburgh
LLB (Hons)
University of Edinburgh


Toshiba—global proceedings—appeal to Court of Justice of the EU and current appeal to General Court
Jacquelyn is representing Toshiba Corporation in multijurisdictional proceedings concerning Gas Insulated Switchgear. This involved a successful appeal of the original European Commission decision fining Toshiba €90.9 million for participating in a global cartel to the European General Court—where the Court annulled in full the fine on Toshiba—and a further appeal to the Court of Justice of the EU. An appeal to the General Court is now pending of the new, lower, fine imposed by the Commission.

Major multinational—customs issue
Jacquelyn represented a major multinational in successful proceedings involving the World Customs Organization, European Commission, national customs authorities and national courts concerning the classification of insulated-gate bipolar transistors.

Toshiba—preliminary ruling to Court of Justice of the EU
Jacquelyn represented Toshiba in a seminal preliminary ruling to the European Court of Justice, which established the principles governing the scope for parallel proceedings by national competition authorities and the European Commission.

US chemicals multinational—customs matters
Jacquelyn advises a US chemicals multinational on a range of high-level customs matters, including rules of origin, tariff quotas and special customs procedures (such as temporary importation).

Toshiba—appeal to European General Court
Jacquelyn is representing Toshiba in an appeal to the Court of Justice of the EU of the Commission Decision in Cathode Ray Tubes (CRT) used for TVs and computer monitors, regarding the conduct of a JV for which it was held liable, having successfully had liability and a fine of €28 million quashed by the European General Court.

Multinational corporations—environmental issues etc.
Jacquelyn is advising major multinational corporations on environmental issues at EU and at national level, as well as handling compliance issues, including inspections by competent authorities, and product recalls.

Toshiba—appeal to Court of Justice of the EU
Jacquelyn represented Toshiba in an appeal to the Court of Justice of the EU against a Commission Decision finding a home market protection agreement in Power Transformers.

Speaking Engagements

EJSF – 4th annual plenary: moderated key panel discussion "Rights under threat – how can the EU Fundamental Rights Charter work better for citizens?", European Economic & Social Committee (EESC), 19 November 2019, Brussels

TRUST Conference "Digital rights: the new frontier of human rights?" 14 November 2019, Queen Elizabeth II Centre, London 

"Chambers D&I Pro Bono Summit panel", fireside chat at the Chambers Diversity & Inclusion European Pro Bono Seminar, 6 November 2019, Amsterdam, Netherlands

"Fundamentals of Business and Human Rights for Lawyers", Legal Ethics Training, Kigali Independent University, 15-18 July 2019, Kigali, Rwanda

Chair, Global Trade and Investment Panel, 58th Annual London-Leiden Conference, King's College London, 29 June 2019

"Killer Acquisitions", Innovation Economics for Antitrust Lawyers, organized by King's College London and Concurrences, 1 March 2019, London

"Proposal for EU Consumer Collective Action System and Review of Class Action Regime", Private Enforcement of Competition Law Conference, 26 February 2019, Brussels

Judge, Jessup International Moot Court Competition 2019, 23 February 2019: Championship Round, Brussels, and 5 April 2019: Semi-final Rounds, Washington, DC

Keynote Speaker: Law for Change: Helping Bhutan Create its First Law School; Panel member: Pro Bono in EU law strategic litigation, PILNet Global Forum, November 2018, Berlin  

Speaker, "Challenges to Human Rights in Times of Transition: Tackling Modern Slavery—Corporations, compliance and operating with a conscience: The role of lawyers", Opening Plenary of the Conference of the Association of Human Rights Institutes, 7 September 2018, Edinburgh University Global Justice Academy, Edinburgh

Speaker, "The Challenges of Algorithms and Competition Law", ULB Summer School (Center for European Law), 5 September 2018, Brussels

Panel Moderator on future of law & sustainability issues, FT-RSG Innovative Lawyers Summit, June 2018, London

Panel speaker, "Extraterritoriality Enforcement: A Rising Concern?", Concurrences Antitrust in Asia Conference, 18 May 2018, Hong Kong

Judge, Jessup International Moot Court Competition 2018, 24 February 2018: Belgian Rounds, Brussels

Panel speaker, "Algorithms and Artificial Intelligence: Beyond Facilitating Concerted Practices, Can They Help Cartel Busters?", Concurrences Innovation Economics for Antitrust Lawyers Conference, 23 February 2018, King’s College, London

Speaker, "Representing companies in global investigations", IBA 12th International Cartel Workshop, 14-16 February 2018, Paris

"Combatting slavery and forced labour", Thomson Reuters Foundation seminar at the World Economic Forum, 25 January 2018, Davos

Panel Speaker, “Business and Human Rights”, ELI Annual Conference, September 2017, Vienna

Speaker, Brexit Roundtable, 24 June 2017: 56th London-Leiden Meeting, London

Workshop Leader, "The Rule of Law", 19-20 June 2017: FT-RSG Innovative Lawyers Summit, London

Moderator, 2nd annual plenary on Access to Justice: Impact of the UN Guiding Principles on Human Rights on lawyers, citizens and business, European Justice Stakeholders Forum (EJSF), April 2017, Brussels

"Jessup's Legacy: Practical Action and New Ideas – The Role of Business in Human Rights", 15 April 2017: Keynote address, Jessup International Moot Court Competition 2017, Championship Round, Washington, DC

"Continental Divide: Differing Approaches to Loyalty Incentives: Rebates as an Abuse of Dominance in the EU and US", 29 March 2017: ABA Antitrust Law Spring Meeting, Washington, DC


"The challenge of ESG for EU competition law", IFLR, February 2021

"EU Competition Law and EU Charter of Fundamental Rights: An Evolving Partnership", foreword to E-Competitions Special Edition "ECHR & Competition law - an overview of EU and national case law", 3 December 2020 (with Bram Vereecken and Aron Senoner)

"The Constitutional Dimension of Case C-673/16 Coman on the Prohibition of Discrimination on the Basis of Sexual Orientation: The Role of Fundamental Rights in Interpreting EU Citizenship", Columbia Journal of European Law, Issue 2, Spring 2020 (with Angela Ward)

Citizenship and Incremental Convergence with Fundamental Rights, Case Note on Coman and Others (Case C-673/16 ECLI:EU:C:2018:385), Cambridge Law Journal, Volume 78 Issue 2, July 2019.

"Innocent until proven guilty – Five things you need to know about killer acquisitions", Comp Law, KNect365, 3 May 2019, (co-author with Tilman Kuhn and Thilo Wienke)

Vertical restraints in an online world: competition authorities gear up their enforcement approach in the digital economy, Competition Law Journal, Vol. 18, No. 1, April 2019 (co-author with J. Jeram and M. Israel)

Co-author, European Union chapter, The Environment and Climate Change Law Review, 3rd edition, 2019 (co-author with Tallat Hussain)

Environment and climate change in the European Union, Lexology Navigator, June 12, 2018, (co-author, with Genevra Forwood, Emma Bichet, Julio-Felipe Pantazis)

European Union chapter, Getting the Deal Through – Risk and Compliance Management, 17 June 2017, (co-author with Stuart Willey)

The Great Repeal Bill – examining the impact on UK international trade, Lexis®PSL, May 22, 2017

Toshiba v. Commission – How (not) to Prove Awareness, and Decisively Influence People, Competition Policy International, August 2016, (co-author, with Aqeel Kadri)

Competition Law in China – an ant on the move?, The Lawyer, May 2012

EC Competition Law Developments, Oxford Yearbook of European Law, 1997–1998, 1999–2000, 2001–2002, 2003–2004, 2005–2006, 2007–2009, 2010, (co-author)

Awards and Recognition

Who's Who Legal: Competition, 2019

Leading Lawyer: Competition/European Law — Belgium, Chambers Europe 2019

Recommended: Competition: EU and global – Belgium, Legal 500 EMEA 2019

Recommended: Customs, trade, WTO and anti-dumping – Belgium, Legal 500 EMEA 2019

Leading Lawyer: Environment: EU Regulatory — Europe-wide, Chambers Europe 2019

Top Ten Innovative Lawyers in Europe – FT Innovative Lawyers 2018

100 Elite Women in Antitrust, Global Competition Review 2016

Best in Competition & Antitrust, Euromoney Women in Business Awards – Europe, 2016 and 2017

Recommended: Not-for-profit – Belgium, Legal 500 EMEA 2018

Leading Lawyer: International Trade/WTO — Europe-wide, Chambers Europe 2017

Leading Lawyer: International Trade/WTO — Belgium, Chambers Europe 2017

Honorary Fellow, Europa Institute, University of Edinburgh

Best Business Anticompetitive Practices Article, 2012 Antitrust Writing Awards

Member of Chatham House

Member of the Environmental Law Network International (elni)

Member of IBA Pro Bono Committee and Human Rights Law Committee

Member of PILnet's Pro Bono Leadership Committee

Member of the ELI-FRA Business and Human Rights Project Team