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Jackie Vallat is a partner in the Antitrust, Competition and Trade Team, based in London and Brussels. She advises on a range of antitrust, merger control and foreign investment control issues, in particular EU and UK antitrust enforcement, and merger control/FDI in international M&A transactions.  Jackie focuses on financial services, energy and TMC (especially media and telecoms). She has extensive experience advising on antitrust and merger control/FDI issues in those sectors.

Jackie also has particular expertise advising on regulatory issues, particularly UK airport regulation and telecoms regulation.  She has a strong telecoms regulatory practice, spanning traditional network operators, digital platforms and infrastructure investors, and advising on transactional as well as regulatory matters (including investigations), in the UK and internationally. 

Jackie is admitted as a solicitor in England and Wales and is on the EU List registered and regulated by the Dutch Brussels Bar.

Jackie is individually ranked as Up and Coming in Chambers and Partners 2026.  She was also recognised as one of the top “40 under 40” foreign investment lawyers globally in the Global Competition Review’s inaugural survey of next generation leading foreign investment lawyers.  

Awards & Recognitions
01
  • Quote
    "She is really excellent. She's very practical and good at cutting through the noise and talking sense."
    Chambers, 2026

Relevant experience

  • Jaguar Land Rover on the parallel European Commission and CMA investigations into end-of-life vehicles.
  • Arora Group on the competition and regulatory aspects of its proposal for Heathrow Airport expansion (including previously on its participation as an interested party in the judicial review claims against the Government’s decision to designate the Airport National Policy Statement).
  • A UK telecoms operator on an investigation by Ofcom into compliance with the General Conditions of Entitlement.
  • Legal & General Capital (Legal & General) on its third investment in ground source heat pump company Kensa, together with Octopus (the biggest investment ever made in ground source tech in Britain). We advised on the multi-jurisdictional merger control and FDI analysis which resulted in unconditional Phase 1 clearance.
  • InstaDeep, a leading global technology company in the field of artificial intelligence and machine learning, on the merger control and foreign investment control aspects of its sale to BioNTech, a next generation immunotherapy company pioneering novel therapies for cancer and other serious diseases. 
  • A consortium comprised of GLIL Infrastructure and Octopus Energy Group on the merger control and foreign investment control aspects of its agreement to acquire a 12.5% interest in the Hornsea One Offshore Wind Farm from Global Infrastructure Partners (GIP). 
  • M&C Saatchi, the international marketing agency, on merger control and foreign investment control aspects of its successful defence of the hostile GBP 264m offer made for it by AdvancedAdvT and on the competitive GBP 310m offer made for it by Next15 Communications Group.
  • Gigaclear, and its principal shareholder, a fund advised by Infracapital, on the merger control/foreign investment control and regulatory aspects of an up to GBP 420m equity investment made by funds managed by Equitix.
  • BT on its agreement with Warner Bros. Discovery, Inc. to form a 50:50 joint venture to create a new sports offering for the UK and Ireland.
  • Cadent Gas on its successful appeal to the CMA of Ofgem’s RIIO-2 gas distribution price control.
  • A global ad tech provider on multiple investigations across the EU (including the UK).
  • Hyperoptic Limited, one of the UK’s largest residential gigabit broadband provider, and its management shareholders on its strategic sale to KKR, a leading global investment firm.
  • Comcast on all media merger control and media regulatory aspects of its ultimately unsuccessful USD 65bn bid to acquire 21st Century Fox.
  • SSE plc on the competition and regulatory aspects of the sale of a 50% stake of its telecommunications business to Infracapital for GBP 380m.
  • A fund manager on the initial stages of the Financial Conduct Authority’s first ever decision using its competition enforcement powers, including responding to the statement of objections.
  • Aviva Investors on the competition and regulatory aspects of several recent acquisitions in the sector, including its GBP 75m stake in Truespeed, GBP 46m investment in County Broadband and GBP 45m investment in ITS Technology Group.
  • Liberty Global on coordinating the media and communications regulatory requirements and notifications relating to the Czech, Hungarian and Romanian aspects of the EUR 18.4bn sale of its European assets to Vodafone.

Publications

  • GCR – Market Review: Cartels 2025 for the UK, with Brian Sher and Claire Barraclough
  • Insurance Broking Practice and the Law, Competition Chapter (co-author)
  • GCR’s Antimonopoly and Unilateral Conduct in the UK (2016 to 2020) with Brian Sher
  • LexisNexis’ TMT Regulation chapter of The Financing of Intangible Assets: TMT Finance and Emerging Technologies (co-author)
  • PLC First Use of FCA competition powers: flexing its muscles (April 2019) with Caroline Hobson, Simon Morris and Alison McHaffie
  • CMS Network Sharing Study 3.0 (December 2017) with Chris Watson and Russell Hoare

Memberships & Roles

  • Member of the Law Society's Competition Section.
  • Women in Telecoms and Technology.

Education

  • 2011 – LPC (Distinction), BPP, London
  • 2010 – GDL (Distinction), Kaplan Law School, London
  • 2008 – LLM (High 2:1), University of Cambridge, Cambridge
  • 2007 – Maîtrise de Droit Economique et des Affaires (Mention Tres Bien), Université de Nice-Sophie Antipolis, Nice (France)
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