Cormac O'Daly

Special Counsel

O'Daly, Cormac

Based primarily in London, Cormac O'Daly advises on a wide range of EU and UK competition law issues. These include merger control, cartels and related litigation, licensing and other vertical and horizontal agreements, other potentially restrictive practices and alleged abuses of market power. He regularly advises on areas at the convergence of competition and intellectual property laws. Mr. O'Daly's clients have ranged from software companies, hardware manufacturers, oil and gas producers, companies appealing fines imposed by the European Commission (including Wabco in its 2013 fine reduction of over € 200 million and Guardian in its 2014 reduction of over € 44 million), companies seeking merger approval, and trade associations. Mr. O'Daly is also a member of the firm's Brexit Group, advising on the potential consequences of the UK leaving the European Union.

Before joining WilmerHale, Mr. O'Daly was an associate in the competition department of a leading firm in London.

Mr. O'Daly also worked as a stagiaire and référendaire to Advocate General Fennelly at the European Court of Justice.

Honors & Awards

  • Winner of Global Competition Review's “Litigation of the Year–Cartel Defence” category 2018 (for work on UK Air Cargo cartel damages case)
  • Listed in the Europe, Middle East & Africa Legal 500
  • Regular contributor to ICC Task Forces on competition policy

Publications & News


April 12, 2018

WilmerHale's Antitrust Group Wins GCR Litigation of the Year Award

Global Competition Review (GCR) has honored WilmerHale's Antitrust and Competition Practice with the award for Litigation of the Year–Cartel Defence, during the GCR Annual Awards Ceremony on April 10.

February 14, 2018

Senior EU Court Adviser Provides Welcome Guidance on Gun-Jumping

EU and US laws prohibit merging companies from implementing reportable transactions until their deal is cleared or the statutory waiting period has expired.

January 16, 2018

EU Merger Control 2017: Competition in Innovation; EC Prohibiting Deals; Fines for Procedural Infringements; and EU Courts Overturning EC Decisions

2017 saw some highly significant investigations and court judgments in European Union merger control.

August 1, 2017

International Merger Remedies

A chapter by John Ratliff, Frédéric Louis and Cormac O'Daly published in The Merger Control Review (8th edition), Chapter 5, pp. 50-62

July 1, 2017

European Union: Abuse of Dominance

A chapter by Frédéric Louis and Cormac O'Daly, published in The European, Middle Eastern and African Antitrust Review 2018, pp. 3-8 (

June 22, 2017

The Brexit Negotiations (2): What is the UK's Opening Position

This is our second Alert on the Brexit negotiation, which started on Monday, June 19, 2017. Having outlined the EU's opening position, we now turn to that of the United Kingdom.

June 20, 2017

The Brexit Negotiations (1): What is the EU's Opening Position?

The Brexit negotiations started yesterday. After months of speculation as to what will be their focus, it may be useful to recall the European Union's opening position and the United Kingdom's opening position.

March 1, 2017

Main Developments in EU Merger Control (2016)

An article by Cormac O'Daly, published in Competition Law & Policy Debate, Vol. 3, Issue 1, March 2017.

September 15, 2016

Brexit and Competition Law: What to Expect

While we wait for the UK to clarify what sort of relationship it will be seeking with the EU after Brexit, it may be useful to highlight what appear to be the main consequences for the enforcement of competition law.

July 30, 2016

International Merger Remedies

A chapter by John Ratliff, Frédéric Louis and Cormac O'Daly published in The Merger Control Review (7th edition), Chapter 4, pp. 46-60 (

Speaking Engagements

June 18, 2015

UK-EU Antitrust and International Anti-Corruption Laws – Recent Developments and How to Respond

London, United Kingdom

April 2, 2015

EuroConference 2015

Brussels, Belgium

September 25, 2012

IBC Legal Conference: IP & Competition Law 2012

Brussels, Belgium

June 22, 2011

Information Exchange in Competition Law

Brussels, Belgium

May 11, 2011

EuroConference 2011

Brussels, Belgium

Recent Highlights

  • Representing merging companies requiring EU, UK and other clearances, notably Baker Hughes when it was acquired by General Electric, Cisco in its acquisition of Tandberg, Oracle in its acquisition of PeopleSoft, and in a European energy sector merger
  • Representing companies in cartel investigations and appeals, including Wabco in its appeal of the European Commission's bathroom fittings and fixtures decision to the General Court, which reduced the imposed fine by over €200 million (the third-largest fine reduction ever in a cartel case) and Guardian in its appeal to the European Court of Justice, which reduced the fine that the Commission originally imposed in its flat glass decision by over € 44 million
  • Acting for a defendant in the air cargo cartel damages action before the UK High Court
  • Counseling on issues at the intersection of competition and intellectual property law including regarding alleged standards essential patents and patent pools
  • Advising on abuse of dominance investigations
  • Advising on potential implications of Brexit
  • Overseeing antitrust compliance in trade associations
  • Litigation before the EU's Court of Justice and General Court including in competition and environmental law and on freedom of access to documents


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LLM, College of Europe, Bruges, 1999, Grade of "Excellent"

LLB (Ling. Franc.), Trinity College, Dublin, 1998, First Class Honours

Bar Admissions

England and Wales, Solicitor

Ireland, Solicitor

Brussels (associate member)





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