He has acted extensively for the International Swaps and Derivatives Association (ISDA), was a principal author of ISDA’s master agreements and has appeared as an arbitrator, mediator and as expert witness in several high-profile derivatives cases. He was formerly the founding partner of the US law practice at Allen & Overy LLP and senior partner in the firm’s global derivatives practice. Before joining Allen & Overy as a partner in 1994, he practiced for more than 15 years in the New York and London offices of the leading Wall Street firm of Cravath, Swaine & Moore.
He currently serves as Founder and Chair Emeritus of The P.R.I.M.E. Finance Foundation in The Hague and is a member of the Foundation’s Panel of Recognised International Market Experts in Finance. He is also an Honorary Fellow and Emeritus Governor at the London School of Economics and Political Science, where he previously held appointments as Visiting Professor and Member of Court.
Jeffrey, his projects and his legal teams have received numerous awards. He recently featured in the Legal 500’s inaugural International Arbitration Powerlist UK of leading arbitration practitioners, and he has topped the rankings for derivatives lawyers and drawn accolades from all leading law firm directories, including, among others, having been hailed as “Mr Derivatives” (Chambers) and “legendary” (Legal 500) and credited with having “written the law on derivatives” (Legal 500).
In 2017, Jeffrey was called as an Honorary Master of the Bench at the Honourable Society of Middle Temple; in 2019, he was awarded the American Bar Association International Lifetime Achievement Award; in 2020, he received the inaugural Lifetime Contributor – Private Practice Award at Law.com/Legal Week’s Legal Innovation Awards 2020 ceremony; and, in 2022, he was appointed Queen’s Counsel Honoris Causa.
Jeffrey was joint Head of Chambers from 2018 to April 2022.
Derivatives & Financial Product Litigation
In the matter of a plan of compromise or arrangement of Just Energy Group, Inc., et al. v NextEra Energy Marketing, LLC
Court File No. CV-21-00658423-00CL (Ontario Superior Court of Justice (Commercial List)) (2022) by expert reports and court testimony.
Lehman Brothers Holdings Inc., et al. v Citibank, N.A., Citigroup Global Markets Ltd., Citigroup Financial Products Inc., Citigroup Engergy Inc., Citi Canyon Ltd. And Citi Swapco Inc.
Case no. 08-13555 SCC, Ad. Proc. No. 12-01044 (2017) by expert report and deposition.
Lehman Brothers Holdings Inc., et al. v Federal Home Loan Bank of New York
Case No. 08-13555 SCC, Ad. Proc. 15-01110 (S.D.N.Y. Bankr.) (2017) by expert report and deposition.
In re Lehman Holdings, et al., Debtors
Case No. 08-13555 SCC, (Claimants QVT Fund LP and Quintessence Fund L.P.) (2017) by expert report and deposition.
Lehman Brothers Holdings Inc., et al. v Federal Home Loan Bank of Cincinnati
Case No. 08-13555 SCC, Ad. Proc. 13-01330 (S.D.N.Y. Bankr.) (2016) by expert report and deposition.
Lehman Brothers Holdings Inc., et al. v Intel Corporation
Case No. 08-13555 SCC, Ad. Proc. 13-01340, 2015 WL 7194609 (S.D.N.Y. Bankr. Sept. 16, 2015) by expert report and deposition.
Lehman Brothers Commodity Services Inc. v. Crédit Agricole Corporate and Investment Bank
Case No. 2010 Folio 79 (2011) (English High Court of Justice, Queen’s Bench Division, Commercial Court).
HSBC Life (UK) Ltd v Stubbs (Inspector of Taxes) (2002) (English Special Tax Commission)
Brookfield Asset Management Inc. and Brysons International Ltd. V AIG Financial Products Corp and American International Group, Inc.
Case No. 09-cv-8285 (RA), (S.D.N.Y.) (2013) by expert report.
Griffin (Inspector of Taxes) v Citibank Investments Ltd. (Jan. 2000)
(English Special Tax Commission), affirmed on appeal (Nov. 2000) (English High Court, Chancery Division).
Jeffrey’s commercial expertise draws on more than 40 years of broad experience from a wide range of corporate and capital markets matters, including swaps and derivatives, international equity and debt offerings, US private placements and listings, and mergers, acquisitions and joint ventures
In the matter of a plan of compromise or arrangement of Just Energy Group, Inc., et al. v NextEra Energy Marketing, LLC
Court File No. CV-21-00658423-00CL (Ontario Superior Court of Justice (Commercial List)) (2022) by expert reports and court testimony.
Lehman Brothers Holdings Inc., et al. v Citibank, N.A., Citigroup Global Markets Ltd., Citigroup Financial Products Inc., Citigroup Engergy Inc., Citi Canyon Ltd. And Citi Swapco Inc.
Case no. 08-13555 SCC, Ad. Proc. No. 12-01044 (2017) by expert report and deposition.
Lehman Brothers Holdings Inc., et al. v Federal Home Loan Bank of New York
Case No. 08-13555 SCC, Ad. Proc. 15-01110 (S.D.N.Y. Bankr.) (2017) by expert report and deposition.
In re Lehman Holdings, et al., Debtors
Case No. 08-13555 SCC, (Claimants QVT Fund LP and Quintessence Fund L.P.) (2017) by expert report and deposition.
Lehman Brothers Holdings Inc., et al. v Federal Home Loan Bank of Cincinnati
Case No. 08-13555 SCC, Ad. Proc. 13-01330 (S.D.N.Y. Bankr.) (2016) by expert report and deposition.
Lehman Brothers Holdings Inc., et al. v Intel Corporation
Case No. 08-13555 SCC, Ad. Proc. 13-01340, 2015 WL 7194609 (S.D.N.Y. Bankr. Sept. 16, 2015) by expert report and deposition.
Lehman Brothers Commodity Services Inc. v. Crédit Agricole Corporate and Investment Bank
Case No. 2010 Folio 79 (2011) (English High Court of Justice, Queen’s Bench Division, Commercial Court).
In re Sears Roebuck Acceptance Corp.
External Review Panel Determination on referral from the ISDA Determinations Committee, decided December 21, 2019
In re Caesars Entertainment Operating Company, Inc.
External Review Panel Determination on referral from the ISDA Determinations Committee, decided February 9, 2015
Jeffrey’s more than 45 years of legal practice has focused almost exclusively on international matters, and his prior appointments include service on the Financial Stability Board’s Market Participants Group for Reforming Interest Rate Benchmarks, the Federal Trust’s working group on European securities regulation; the European Commission’s study group and City of London joint working group on the legal aspect of monetary union; ISDA task forces on the legal aspects of monetary union, including advising ISDA’s Market Practice Advisory Committee; and the European Bank for Reconstruction and Development Local Capital Market Development Legal and Regulatory Assessment Advisory Panel; and his chairmanship of the American Bar Association Section of International Law.
Non-Litigation-Based Expert Appearances:


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