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About Jenny Leahy

Jenny’s practice covers all aspects of EU and UK competition law, including merger control, investigations, abuse of dominance, and compliance and risk management strategies.  Jenny also advises clients on navigating global foreign investment regimes, including the UK NS&I regime.  

She has experience of advising clients across a wide range of industries, with a particular focus on the life sciences, consumer goods and financial services sectors. Highlights include advising on high-profile, complex merger control transactions, including public takeovers. She has experience of engaging with antitrust agencies around the world and is a pragmatic, commercially minded lawyer.

Based in London, Jenny has also spent time on secondment to our Washington DC and Brussels offices.  

She chaired the Freshfields London Women’s Network and is a founding member of the UK branch of W@Competition.

Jenny is fluent in Dutch and English.

Recent work

  • Advising Alexion, AstraZeneca Rare Disease, on its acquistion of LogicBio, a genomic medice company
  • Acting for London Stock Exchange Group on its $27bn acquisition of Refinitiv, a financial information, data and analytics provider, which required review by 20 antitrust authorities worldwide, including in-depth merger reviews in the EU and US, as well as foreign investment reviews in several jurisdictions.
  • Advising Honeywell on the combination of Honeywell Quantum Solutions and Cambridge Quantum Computing and acquisition of a majority stake in the combined company.
  • Advising AstraZeneca on its $8.5 billion strategic oncology collaboration with Merck.
  • Advising AstraZeneca on its $6 billion global development and commercialisation agreement with Daiichi Sankyo.
  • Advising Comcast on the global merger control and public interest aspects of its £30bn public bid for Sky plc, including achieving unconditional Phase 1 clearance from the European Commission, and advising on the global merger control and public interest aspects of its $66bn bid for the global assets of 21st Century Fox.Read more about the deal in our case study.
  • Advising Experian plc on the CMA's Phase 2 investigation into its proposed acquisition of ClearScore.
  • Acting for London Stock Exchange Group on its recommended £21bn merger with Deutsche Börse.
  • Advising M&G Asset Management in relation to the FCA’s asset management market study.
  • Advising ChemChina on the global merger control and foreign investment aspects of its $1bn acquisition of industrial machinery maker KraussMaffei Group and its $8bn public bid for Italian tyre giant Pirelli, which required clearance in over 15 jurisdictions.
  • Advising Betfair on its £5bn merger with Paddy Power.
  • Assisting a major financial institution on the global investigations into alleged foreign exchange manipulation.


University education

  • King's College London (Postgraduate Diploma in Economics for Competition Law)
  • University College London (LLM in EU Competition Law with postgraduate distinction)
  • University of Maastricht, Netherlands (LLB)

Professional qualifications

  • Solicitor, England and Wales
  • Member of the Brussels Bar (E-List)

Additional responsibilities

  • Editorial Board, Journal of Antitrust Enforcement (Oxford University Press)