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Dennis J. Block is the Senior Chairman of Greenberg Traurig's Global Mergers & Acquisitions practice, based in the New York office. Greenberg Traurig has approximately 2,750 lawyers in 47 U.S. and international offices, including a global corporate practice of more than 500 lawyers. Mr. Block's practice is national and international in scope.

Mr. Block is known for precedent-setting transactions. These include:

  • Pfizer Inc.'s $68 billion acquisition of Wyeth, the largest M&A transaction of 2009;
  • P&G's acquisition of Gillette;
  • Westinghouse's acquisition of CBS Corp;
  • Bear Stearns Companies Inc. acquisition by JPMorgan Chase; and
  • US West's acquisition of Continental Cablevision and its subsequent split-off and joint venture with Time-Warner and the ultimate sales of both US West (to Qwest Communications) and Media One (to AT&T).

Mr. Block also represented Pfizer, Inc in connection with its:

  • $100 billion hostile acquisition of Warner-Lambert, the largest domestic hostile takeover to date;
  • $60 billion acquisition of Pharmacia;
  • acquisition of King Pharmaceuticals, Inc.; and
  • its sale of the Capsugel business to KKR.

In 2010, he was named for the third time as an American Lawyer Dealmaker of the Year, for serving as counsel to Pfizer in its acquisition of Wyeth. Mr. Block has consistently been ranked in the first tier as one of the leading corporate/M&A lawyers by Chambers and Partners in its US and global editions. Mr. Block advises a broad range of entities including companies, boards of directors and special committees on corporate governance, M&A and related matters. Prior to entering private practice, he was a branch chief for enforcement in the New York Regional Office of the Securities and Exchange Commission.

Mr. Block has been co-chairman of the Committee on Corporate Counsel and a member of the Council of the Section of Litigation of the American Bar Association. From 1993-1998, Mr. Block served as a member of the Committee on Corporate Laws of the Section of Business Law of the American Bar Association.

He has co-authored The Business Judgment Rule: Fiduciary Duties of Corporate Directors (5th ed. 1998 and Supp. 2000). He was also co-author of a monthly column in the New York Law Journal, co-editor of The Corporate Counsellor's Deskbook (5th ed. 1999), and a member of the editorial boards of several legal publications.

Mr. Block frequently lectures on mergers and acquisitions, the business judgment rule, corporate governance, federal securities law, corporate litigation, the attorney-client privilege and indemnification and insurance of corporate officials.

Mr. Block is a graduate of Brooklyn Law School, where he taught advanced corporate law as an adjunct professor. He holds a BA from the State University of New York at Buffalo.


  • Mergers and acquisitions
  • Private equity
  • Proxy contests
  • Joint ventures 
  • Third-party/self-tender offers 
  • Other corporate restructurings 
  • Corporate governance and board representation 
  • SEC matters 
  • Finance 
  • Risk and crisis management



  • DPL in its acquisition by AES Corp.
  • Pfizer Inc. in its acquisition of King Pharmaceuticals, Inc.
  • Pfizer Inc. in its acquisition of Wyeth
  • Pfizer Inc. in its sale of the Capsugel business to KKR
  • Bear Stearns Companies Inc. acquisition by JPMorgan Chase
  • Pfizer Inc. in the sale of its Consumer Business to Johnson & Johnson
  • Republic Bancorp Inc. in its merger with Citizens Banking Corporation
  • The Procter & Gamble Company in its acquisition of The Gillette Company
  • Pfizer Inc. in its acquisition of Vicuron
  • StorageTek in its acquisition by Sun Microsystems
  • Pfizer Inc. in its acquisition of Pharmacia Corporation
  • Quaker Oats in its acquisition by PepsiCo Inc.
  • The Bear Stearns Companies Inc., financial advisor to General Motors, in connection with the sale of GM’s subsidiary, Hughes Electronics Corporation, to EchoStar Communications Corporation
  • Houghton Mifflin Co. and the special committee of its board in its acquisition by Vivendi Universal
  • Pfizer Inc. in its acquisition of Warner-Lambert
  • US West in its merger with Qwest
  • US West in its merger with Global Crossing 
  • Investment bankers for RJR Nabisco in its acquisition by KKR
  • NCR and its merger with AT&T
  • MediaOne and its merger with AT&T
  • The General Electric in its attempted acquisition of Kemper Insurance
  • US WEST and its acquisition of Continental Cablevision and US WEST’s joint venture with Time-Warner and its subsequent split-off of MediaOne Group
  • Westinghouse in its acquisition of CBS
  • Macy’s in its takeover fight with Federated Department Stores
  • J.C. Penney in its acquisition of Eckerd Drugs
  • Bally's in its acquisition by Hilton Hotels and the subsequent split-off of Park Place Entertainment
  • Toys “R” Us in its acquisition of Baby Superstores
  • Dresser Industries in its merger with Halliburton
  • Arbor Drugs in its acquisition by CVS
  • NacRe in its acquisition by XL

°Certain of the above representations were handled by Mr. Block prior to his joining Greenberg Traurig, LLP.

  • Business Law Currents Editorial Board, Thompson Reuters, 2011
  • Board of Contributing Editors and Advisors, Securities Regulation Law Journal, 1979-present
  • Board of Contributing Editors and Advisors, The Corporate Law Review
  • Editorial Board, Inside Litigation, Prentice Hall Law & Business
  • Editorial Board, Insights, Prentice Hall Law & Business, 1987-present
  • Advisory Board of Securities Regulation & Law Report, Bureau of National Affairs, Inc.
  • Editorial Board, Corporation
  • Board of Editors of Advisors, Executive Counsel
  • Editorial Board, Mergers and Acquisitions Law Reporter
  • Editorial Board, The Corporate Governance Advisor
  • Board of Editors, The M&A Lawyer

Recognition & Leadership

  • Listed, Who's Who Legal, "Thought Leaders - M&A and Governance," 2023
  • Listed,The Best Lawyers in America, 2006-2024
    • Corporate Law, 2006-2024
    • Mergers and Acquisitions Law, 2006-2024
    • Corporate Governance Law, 2006-2021
  • Listed, Chambers USA Guide, 2003-2024
    • "Senior Statespeople," 2024
    • "Eminent Practitioners," 2014-2023
  • Listed, The Legal 500 United States
    • M&A Corporate and Commercial - M&A: Large Deals ($1bn+), 2016-2019
    • Mergers, Acquisitions and Buyouts - M&A: Large Deals - Leading Lawyers, 2012-2015
    • “M&A Private Practice Powerlist – USA Region,” 2023-2024
  • Listed, Super Lawyers magazine, New York Metro Super Lawyers, 2006-2023
    • Listed, "Top 100 Lawyers in New York," 2013
  • Listed, Thomson Reuters, "Stand-Out Lawyers," 2022-2024
  • Listed, Acritas Stars™ Independently Rated Lawyers, "Star Lawyers," 2018-2021
  • Listed, Chambers Global
    • Corporate/M&A (International & Cross-Border), 2023-2024
      • "Eminent Practitioner," 2023-2024
    • Corporate/M&A (USA), 2015-2023
      • "Eminent Practitioner," 2015-2023
  • Team Member, Corporate Board Member magazine and FTI Consulting Inc., one of "America’s Best Corporate Law Firms," 13th Annual Legal Industry Study, 2013
  • Named, Client Service All Star, BTI Client Service All-Stars Report, 2012
  • Listed, Euromoney’s Guide to the World’s Leading Mergers and Acquisitions Lawyers, 2011
  • Listed, Lawdragon 500, "Leading Lawyers in America," 2011
  • Named, "Dealmaker of the Year," The American Lawyer, 2000, 2003 and 2010
  • Named, "Most Influential Lawyers in America," The American Lawyer, 2006
  • Rated, AV Preeminent® 5.0 out of 5.0

°AV®, AV Preeminent®, Martindale-Hubbell DistinguishedSM and Martindale-Hubbell NotableSM are certification marks used under license in accordance with the Martindale-Hubbell® certification procedures, standards and policies.

Dennis is an active leader in the legal community. Recent roles are highlighted below.

  • The Fellows of the American Bar Foundation, 1988-Present
  • American Bar Association, 1969-Present: Dennis has dedicated over 30 years to the American Bar Association serving as a leader and mentor.
    • Section of Litigation
      • Chairman, Task force on Ancillary Business Activities of Lawyers, 1983-1993 
      • Co-chairman, Committee on Corporate Counsel, 1982-1985
      • Division Director, 1985-1986 
      • Committee on Securities Litigation, 1988-Present
      • Council of Section of Litigation, 1986-1989 
    • Section of Business Law
      • Committee on Corporate Laws, 1993-1998 
      • Chairman, Drafting Committee, Comment Letter on SEC Proposed Rule 24a-1, Litigation Subcommittee on Committee on Federal Regulation of Securities
      • Drafting Committee, Comment Letter on SEC Proposed Rule 14d-8, Tender Offer and Proxy Statement, Subcommittee on Federal Regulation of Securities, 1990
      • Committee on Federal Regulation of Securities, 1988-Present
      • Subcommittee on SEC Practice and Enforcement Matters, 1988-Present 
      • Subcommittee on Proxy Solicitations and Tender Offers, 1988-Present 
      • Committee on Counsel Responsibility and Liability, 1988-Present 
      • Committee on Business and Corporate Litigation, 1991-Present 
    • Subcommittee on Ancillary Business Activities of the American Bar Association’s Special Coordinating Committee on Professionalism, 1989-1991
  • UJA-Federation of New York, Lawyers Division
    • Past chairman, 1989-1991
    • Major Gifts chairman, 1987-1989
  • Member Emeritus, Board of Trustees, Brooklyn Law School, 2024-Present
  • Board of Trustees, Brooklyn Law School, 2017-2024
  • Adjunct Professor, Brooklyn Law School, 1999-2019
  • Board of Directors, Junior Achievement of New York (JANY), 2005-2017 
  • Board of Trustees of Supreme Court Historical Society, 2010-Present
  • The American Law Institute, 1983-Present
  • The Association of the Bar of the City of New York, 1984-Present
  • American Society of Corporate Secretaries, 2000-2011 
  • Law Firm Advisory Committee of the Metropolitan Corporate Counsel, 1993-1998
  • New York State Governor’s Task Force on Commercial Courts, 1992-1993


  • LL.B., Brooklyn Law School, 1967
  • B.A., State University of New York at Buffalo, 1964
  • New York