McDermott Boosts its Global Competition Capabilities with Partner Hire in Brussels - McDermott Will & Emery

McDermott Boosts its Global Competition Capabilities with Partner Hire in Brussels


Brussels, November 2, 2022 – International law firm McDermott Will & Emery announced today the appointment of Stéphane Dionnet as partner in its office in Brussels. Stéphane joins McDermott’s global antitrust practice and his arrival will further bolster the Firm’s European competition capabilities as he will be working alongside seasoned specialists including Jacques Buhart, Hendrik Viaene in Brussels, Christian Krohs and Carina Kant in Düsseldorf, Frédéric Pradelles and Matthieu Adam in Paris and the Firm’s US antitrust team in Washington, New York and Chicago.

Stéphane has over 20 years of experience focusing on European Union competition laws. He has advised global corporations in navigating complex EU and multijurisdictional merger control matters and has represented clients in numerous cartel investigations. In addition, he has experience across a wide range of sectors including consumer products, energy, entertainment, financial services, technology, pharmaceuticals, retail, e-commerce and telecommunications.

On the merger side, Stéphane has advised ABB on all the antitrust aspects of its largest acquisition when it purchased General Electric’s industrial solutions business and more recently, when the company divested 80.1% stake in its Power Grids division to Hitachi, Ltd. He also represented Xilinx, Inc. in all antitrust aspects of its US$49 billion acquisition by Advanced Micro Devices, Inc assisting in securing regulatory clearances from several competition agencies, including the European Commission, the Competition and Markets Authority, and the State Administration for Market Regulation in China; Stéphane also represented DSV AV in its acquisitions of UTi Worldwide Inc. (US$1.34 billion), The Panalpina Group (US$4.6 billion) and more recently the global integrated logistics business of Agility Public Warehousing Company K.S.C.P. (US$4.2 billion).

On the cartel side, Stéphane advised ABB Ltd in the context of the Power Cables investigation, including the representation before the European Court of Justice in its partial successful appeal against the General Court’s Power Cable Cartel judgment. He regularly advises companies confronted with damage actions following violation of competition rules. Stéphane has also successfully assisted companies in obtaining leniency from the European Commission and other competition agencies.

“With the international competition landscape remaining as busy as ever, we are delighted to be bringing in such an experienced practitioner to service our clients’ sophisticated needs,” said Ray Jacobsen, Global Head of McDermott’s Antitrust practice. “Increasingly complex enforcement policies are one of the critical factors determining successful business strategies. McDermott continues to grow its strong antirust bench to support our clients in fulfilling their commercial objectives.”

“McDermott represents some of the largest global businesses and Stephane’s solid track record in steering high-profile clients towards successful outcomes in their multi-billion-dollar transactions will provide a further boost to our EU practice. His significant experience in merger control and cartel investigations matters is also an excellent fit with our European and global areas of strength,” added Hendrik Viaene, Head of the Firm’s Brussels office.

Earlier in his career, Stéphane worked within the Merger team of the European Commission’s Directorate-General for Competition. He was a case-handler in high-profile mergers, including phases 1 and 2 with remedies.

“McDermott’s Global Antitrust practice has an outstanding reputation in assisting clients in overcoming hurdles in complex regulatory environment,” said Stéphane. “I’m very excited to be joining the Brussels team which is closely aligned with the Firm’s strong competition practices in France, Germany and the US. I’m also looking forward to spearheading my own practice within McDermott’s interconnected competition platform,” he added.


With an outstanding global Antitrust & Competition team of c.65 lawyers across offices in Brussels, Chicago, Düsseldorf, New York, Paris and Washington DC, McDermott continues to expand its international footprint with a spate of high-profile appointments over the last couple of years,  including four antitrust veterans in the US with deep experience in private and government sectors. Last year, European heavyweight additions to the practice included Brussels, Hendrik Viaene, specialist of State Aid, and Frédéric Pradelles in Paris, with outstanding experience in fields including merger control, and international cartel defence, distribution and international trade.

In Brussels, McDermott has hired earlier this year a team of five lawyers lead by Rosa Barcelo, specialist of privacy and cybersecurity working closely with our privacy teams in Paris and the US.

About McDermott

McDermott Will & Emery partners with leaders around the world to fuel missions, knock down barriers and shape markets. Our team works seamlessly across practices and industries to deliver highly effective solutions that propel success. More than 1,200 lawyers strong, we bring our personal passion and legal prowess to bear in every matter for our clients and the people they serve.

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