Paul Weiss

1285 Avenue of the Americas
New York, NY 10019-6064
212-373-3231 (direct)
212-492-0231 (direct fax)
212-373-3000 (firm)
212-757-3990 (firm fax)

A senior partner in the Litigation Department, Les Fagen has litigated on behalf of both plaintiffs and defendants for more than 35 years, handling his clients’ most complex civil litigation matters.


Les has a strong track record of wins and favorable settlements at the trial and appellate levels in federal and state courts in multiple jurisdictions, and in alternative dispute resolution proceedings. Some of his illustrative case work includes:

  • representation of major private equity companies and hedge funds in substantial commercial disputes concerning transactional matters and securities litigation and regulation;
  • representation of major public company defendants in significant securities litigations, antitrust and transactional matters and internal investigations;
  • representation of clients in major international and domestic arbitrations, including his role as lead trial counsel for Citigroup defending a $7.5 billion dollar claim brought by the Abu Dhabi Investment Authority in which an arbitration panel ruled in Citigroup's favor;
  • representation of clients in the media, fashion and information services fields in intellectual property matters including trademark, copyright and licensing disputes;
  • representation of major manufacturers in product liability defense work, including class action litigation in Texas, New York, New Jersey, Pennsylvania, Ohio, California, Illinois, Florida, South Carolina and Oklahoma, and the prosecution of plaintiffs' claims relating to defective products;
  • representation of clients in real estate litigation matters including appraisal arbitrations;
  • representations of clients in significant trusts and estates matters; and
  • a court appointment to represent all future claimants who fall victim to asbestos-related disease in connection with the Manville Personal Injury Settlement Trust.

Les' major client representations have included Citigroup, Inc., Inc.UBS AGJPMorgan Chase & Co.BNY MellonViacom Inc.Dun & Bradstreet, Inc.American International GroupHarbinger Capital PartnersParamount Pictures CorporationExor GroupCBS CorporationMTV NetworksShowtime NetworksMadison Square GardenACNielsen & Co.The Nielsen CompanyNielsen Media Research CorporationWilliam Morris Endeavor Entertainment LLC General AtlanticVeolia EnvironnementBecton Dickinson & CompanyAisin AW Co., Ltd., Tokyo Electric Power Company, Inc.Perella Weinberg Partners LP, Reservoir Capital Group, LeFrak Organization, Alix Partners, Citco Corporate Services, Inc.Hollinger InternationalCognizant CorporationWachovia CorporationKohlberg & Co.Walter Energy, Inc., Time Warner Inc.Merrill Lynch & Co.Christie's, Lazard Fréres & Co.IMS HealthPolo Ralph Lauren CorporationLiz Claiborne, Inc.The Children's Place Retail Stores, Inc.Michael Kors (USA), Inc., Calvin Klein, Inc.AmtrakThe Metropolitan Transportation AuthorityThe New York City Transit AuthorityThe Long Island Rail RoadThe Huffington Post, Suzuki Motor CorporationThe United Bank of KuwaitKate Spade, Inc.Buzzfeed,, Martha Stewart Living Omnimedia, Inc.HEB and Hochschild Mining plc.

Les' work on behalf of ACNielsen & Co. and other clients was profiled in an American Lawyer cover story, "The Lifesavers," in which Paul, Weiss was selected as the best litigation firm in the United States. He is noted as a leading practitioner in commercial litigation by Chambers USA, Benchmark Litigation and The International Who's Who of Business Lawyers. He has been named by his peers in The Best Lawyers in America as a leader in the fields of "Bet-the-Company," commercial and intellectual property litigation. He has been recognized as an "excellent trial lawyer and general counselor" in Legal 500 and a leading attorney in the competition and product liability litigation fields in Lawdragon 500.

Les is a Fellow of the American College of Trial Lawyers, where he serves on the Judiciary Committee.

Les is an adjunct lecturer in law at Columbia Law School, where he teaches trial advocacy, and an adjunct professor of law at Brooklyn Law School, where he teaches an intellectual property litigation course. Les is also an Associate Fellow, Berkeley College, Yale University.

He has been a member of the firm's Management Committee. He is a former Chairman of the Partnership Committee and has served as Co-Chair of the firm's Litigation Department.

Les is a member of the Association of the Bar of the City of New York, the International Bar Association and the Legal Advisory Board of the Copyright Alliance. He has also served on several City Bar committees, including Committees on the Judiciary, State Legislation and Transportation. Les has been a member of the American Bar Association and the New York State Bar Association Section of Commercial and Federal Litigation, where he served as chairman of the Committee on Magistrate Judges. He won, as co-author, the New York State Bar Association Commercial and Federal Litigation Section's award for "Excellence in Commercial Brief Writing."

Les is a director of the Lawyers Committee for Civil Rights Under Law. He has served as President and Vice Chairman of The Educational Alliance, Inc., a multi-disciplinary social service agency, and as a member of the Board of Trustees of Maimonides Medical Center. He has been a David Rockefeller Fellow at the Partnership for New York City. He currently serves on the Development Board of The Bingham Centre for The Rule of Law and the International Rule of Law Project, Inc., an affiliate of the Bingham Centre.

Les is the author of numerous publications on arbitration, intellectual property and product liability. He is also the author of a monograph on the life of the firm's late patriarch Judge Simon H. Rifkind published in The Yale Biographical Dictionary of American Law. Ed. Roger K. Newman. New Haven, CT. Yale University Press, 2009. 459.

Les is a member of The Century Association.



  • J.D., Columbia Law School
  • B.A., Yale College


  • Hon. Jack B. Weinstein, U.S. District Court, Eastern District of New York

Bar Admissions

  • New York
  • District of Columbia

See Library Tab for articles, publications and presentations by Leslie Fagen

Related Resources

Nov 05, 2015 | News

Walter Energy Enters APA in its Restructuring

Sep 30, 2015 | News

Thrillist Splits Off JackThreads

Sep 14, 2015 | News

WME IMG Acquires Miss Universe Organization From Donald Trump

Mar 30, 2015 | News

New York Court Dismisses Investor Lawsuit Against Philip Falcone and Harbinger Capital 

Mar 25, 2015 | Publications

The Supreme Court Holds That the Trademark Trial and Appeal Board’s “Likelihood of Confusion” Decisions Are Eligible for Issue Preclusion in Federal Court

Feb 24, 2015 | Events

Les Fagen Speaks at NYU Annual Survey of American Law Ceremony

Jan 07, 2015 | News

Preliminary Settlement Reached in Lawsuit Challenging Police Practices in NYC Public Housing

Dec 24, 2014 | News

MTA Wins Major Second Circuit Victory

Oct 26, 2014 | News

Paramount Pictures Achieves Major Trial Victory

Jun 30, 2014 | News

Kohlberg Completes Acquisition of Troon Golf

Jun 19, 2014 | News

Paul, Weiss Obtains Vacatur of Class Certification Order for Citco

May 06, 2014 | News

William Morris Endeavor Closes Acquisition of IMG

Feb 19, 2014 | News

Second Circuit Affirms Confirmation of Arbitral Award for Citigroup

Jan 09, 2014 | News

Elliott Management and Compuware Reach Agreement 

Dec 31, 2013 | News

Center for Popular Democracy, Inc. Completes Merger with The Leadership Center for the Common Good

Dec 18, 2013 | News

William Morris Endeavor Announces Acquisition of IMG

Oct 16, 2013 | News

Summary Judgment Granted in Class Action Against MTA

May 22, 2013 | News

All Claims Against The Bank of New York Mellon Dismissed

Mar 04, 2013 | News

Nielsen Achieves Victory in Monopolization Case

Nov 15, 2012 | Videos

Mediation: Tactics for Successfully Resolving Disputes

Of Note

Jan 29, 2015

Benchmark Litigation Names Paul, Weiss “Antitrust Firm of the Year”

Jun 07, 2013

Chambers USA 2013 Ranks Paul, Weiss Highly

Thank you for your interest in Lawdragon.