Pat Treacy
Partner
- London/Brussels
- pat.treacy@bristows.com
- +44 20 7400 8373/+32 2 400 6232

Pat has specialised in EU law and competition law since the 1980s, handling landmark cases at EU and national level and helping clients from all over the world with their competition law needs.
Recognised as a leading adviser on the legal and policy issues that come up when competition law and intellectual property law meet, many of Pat’s clients are in technology rich sectors.
Pat works with clients on transactions and complex agreements (including settlement, R&D, licensing and joint venture agreements) in all sectors, with a focus on high tech and pharma/life sciences. Given the confidentiality concerns that are prevalent in innovative industries, Pat has substantial experience of advising on competition law in arbitrations, as well as before the competition authorities in Brussels and London and in Court proceedings at national and EU level.
Pat advises regularly on the competition law responsibilities of dominant companies – particularly where IP is concerned. She and her team help with competition compliance and “dawn raids”, supporting clients through such dawn raids and their aftermath.
Pat was appointed Deputy High Court Judge in September 2018, and will serve in the Chancery Division of the High Court of England and Wales for six years. This part time appointment enables Pat to continue as a Partner, leading the team and working with clients.
Pat is a member of the Competition Law Association; the UK Association of European Lawyers; and the Competition Section of the Law Society. She is on the editorial board of both the Journal of Intellectual Property Law and Practice and Competition Law Insight. Pat lectures and writes widely on topical issues. She also teaches the competition law module on the University of Oxford Postgraduate Diploma in Intellectual Property Law and Practice course.
What others say
Recommended For
Competition Law
Chambers and Partners 2021
Competition Law: Litigation
Chambers and Partners 2021
Competition Litigation (leading individual)
Legal 500 2021
EU and Competition
Legal 500 2021
Technology, Media and Telecoms
Legal 500 2021
Competition Law and Information Technology Law
Best Lawyers™ UK 2021
Competition Law
Chambers and Partners Global 2020
Competition Law: Litigation
Chambers and Partners Global 2020
Competition Law
Chambers and Partners Europe 2020
Competition Litigation
Chambers and Partners Europe 2020
Competition
Who’s Who Legal: Leading Individual 2020
Competition
Who’s Who Legal: Thought Leader 2020
Competition/ European Law: Non-contentious
Chambers and Partners 2019
Competition and Antitrust: Leading practitioner
Expert Guides: Women in Business Law 2019
Competition
Who’s Who Legal Worldwide Thought Leaders 2019
Pharmaceuticals and Biotechnology
Legal 500 2017
Competition Team of the Year
The Lawyer Awards 2017