Hal J. Leibowitz


  • Co-Chair, Mergers and Acquisitions Practice

Hal Leibowitz is co-chair of WilmerHale's Mergers and Acquisitions Practice Group. He has previously served as chair of the firm's Corporate Practice and as vice chair of the Transactional Department. Mr. Leibowitz's practice focuses on corporate and securities law matters for companies in the life sciences, technology and services industries, with an emphasis on mergers and acquisitions and public company counseling.

Among the clients he represents are Akamai Technologies, Analogic, The Boston Consulting Group, Ensign-Bickford Industries, Hasbro, Houghton Mifflin Harcourt Publishing Company, Kadant, Kala Pharmaceuticals, MKS Instruments, PAREXEL International, PerkinElmer, Progress Software, PTC Therapeutics, Thermo Fisher Scientific and Xcerra Corporation.

Mr. Leibowitz has served as counsel in a wide range of merger and acquisition transactions, including acquisitions and dispositions of numerous public and private companies, tender offers, exchange offers, and going private transactions.

Professional Activities

Mr. Leibowitz is a member of the American, Massachusetts and Boston Bar Associations and a member of the American Bar Association's Section on Business Law, where he has served as chair of the Merger and Acquisitions Committee's Market Trends Subcommittee and on the Editorial Board of the Committee's Subcommittee on Public Company Acquisitions. In addition, he has chaired the ABA Market Trends Subcommittee's annual survey of deal points in the acquisition of public companies. Mr. Leibowitz is also a member of the Thomson Reuters Governance, Risk and Compliance Partner Advisory Board, a think tank that discusses pressing issues facing the legal industry and formulates solutions to help colleagues run more effective businesses.


  • Life Sciences Transactions

    • Aspect Medical in its acquisition by Covidien
    • Corvia Medical in its strategic investment by Edwards Lifesciences
    • Cynosure in its $1.65 billion acquisition by Hologic
    • Enobia Pharma in its acquisition by Alexion Pharmaceuticals
    • Eyetech Pharmaceuticals in its $935 million acquisition by OSI Pharmaceuticals
    • General Catalyst, the largest shareholder of Livongo, in the $18.5 billion merger of Livongo and Teladoc Health
    • Icagen in its acquisition by Pfizer
    • Infinity Pharmaceuticals in its proposed merger with MEI Pharma
    • The Medicines Company in its acquisition of Targanta Therapeutics
    • Millennium Pharmaceuticals in its $9 billion acquisition by Takeda Pharmaceuticals
    • Palomar Medical Technologies in its acquisition by Cynosure
    • PAREXEL International in its acquisitions of ExecuPharm, Health Advances and Heron Group Limited
    • PerkinElmer in the divestiture of its Applied, Food and Enterprise Services businesses to New Mountain Capital for up to $2.45 billion, in its $5.25 billion acquisition of BioLegend, in its acquisitions of Oxford Immunotec, Caliper Life Sciences, Signature Genomic Laboratories and ViaCell, in the divestiture of its illumination and detection solutions and aerospace businesses and in the divestiture of its medical imaging business to Varian Medical Systems
    • PTC Therapeutics in its acquisitions of certain assets of Marathon Pharmaceuticals and BioElectron Technology and its acquisition of Agilis Biotherapeutics
    • Sepracor in its $2.6 billion acquisition by Dainippon Sumitomo Pharma
    • Tetraphase Pharmaceuticals in its merger with La Jolla Pharmaceutical Company and its previous agreements to be acquired by each of AcelRx Pharmaceuticals and Melinta Therapeutics 
    • Thermo Fisher Scientific in its acquisitions of Finesse Solutions, Alfa Aesar, Advanced Scientifics, One Lambda, Phadia Group ($3.5 billion), Fementas International, Cohesive Technologies, Priority Solutions, the Kendro Laboratory Products division of SPX Corporation, Gatan and the cell sorting technology assets of Propel Labs; and in divestitures of its Anatomical Pathology ($1.1 billion), Cell Culture ($1.0 billion), Cole-Palmer, Gene Modulation, Magnetic Particles, Athena and Lancaster Laboratories businesses
    • Tokai Pharmaceuticals in its acquisition of Otic Pharma
  • Technology Transactions

    • Akamai in its acquisitions of Noname Security, Linode, Asavie Technologies ($900 million), Exceeda, Guardicore, Janrain, Soha Systems, Bloxx, Octoshape, Prolexic, Cotendo, Speedera Network, Nine Systems and Netli, and in the divestiture of its Advertising Decision Solutions business
    • Altiostar Networks in its $1 billion sale to Rakuten
    • Analogic Corporation in its acquisitions of Ultrasonix Medical and Oncura Partners and in its acquisition by an affiliate of Altaris Capital Partners for $1.1 billion
    • Applix in its acquisition by Cognos
    • Bookham Technology in its acquisition of New Focus
    • Keane in its acquisition by Caritor and in its acquisitions of Metro Information Systems and Signal Tree Solutions
    • LTX Corporation in its combination with Credence Systems, its proposed combination with Verigy Ltd. and its acquisition of the Multitest and Everett Charles Technologies businesses of Dover Corporation
    • MKS Instruments in its proposed $6 billion acquisition of Coherent and in its acquisition of Newport Corporation
    • Netezza in its $1.7 billion acquisition by IBM
    • Oasis Semiconductor in its sale to SigmaTel, Inc.
    • Progress Software in its acquisitions of Chef Software, Ipswitch, IONA Technologies, Kemp, Rollbase and Telerik and in the divestiture of its Apama, Orbix, Artix, Orbacus, Sonic, Savvion, Actional, DataXtend and Shadow product lines
    • RSA Security in its $2.3 billion acquisition by EMC Corporation and in its acquisitions of Cyota, 3-G International, XCert International, Intrusion Detection, DynaSoft and PassMark Security
    • Skillsoft PLC in its acquisition by a new company formed by funds sponsored by each of Berkshire Partners, Advent International and Bain Capital
  • Industrial and Other Transactions

    • A global institutional investor in the proposed merger of equals transaction between DraftKings and FanDuel
    • ASICS in its acquisitions of FitnessKeeper and Fast North
    • The First Marblehead Corporation in its acquisition by FP Resources USA Inc.
    • Houghton Mifflin Harcourt in the divestitures of its HMH Books & Media, Riverside clinical and standardized testing, Curious World and Adult Education businesses, in its acquisition of the Waggle adaptive learning solution business and in its acquisition by affiliates of Veritas Capital for $2.8 billion
    • Kadant in its acquisitions of The Johnson Corporation and Syntron Material Handling Group
    • Lydall in its acquisition of Interface Performance Materials and in its divestiture of Charter Medical
    • Saucony in its sale to The Stride Rite Corporation


  • Award Text

    Recognized as a Massachusetts Leader for Corporate/M&A

    Chambers USA


  • Award Text

    Named Among the Best Lawyers in America for Corporate Law

    Best Lawyers in America 


  • Award Text

    Named a Leading Lawyer for Middle-Market M&A

    The Legal 500 United States


  • Named a Thomson Reuters Stand-out Lawyer – independently rated and selected by clients
  • Recognized as a Massachusetts leader in the corporate/M&A field in the 2006–2024 editions of Chambers USA Guide.
  • Selected by his peers in the 2012–2024 editions of the Best Lawyers in America in the area of corporate law.
  • Repeatedly recognized by The Legal 500 United States for his middle-market M&A practice and selected for inclusion in The Legal 500’s 2023 and 2024 M&A Powerlist - USA Region. 
  • Named to Boston Magazine’s inaugural Top Lawyers list in 2021 and 2022 in the area of corporate law.
  • Selected by LMG Life Sciences as winner of its "Canadian Impact Deals of the Year" in 2013 award for representation of Enobia Pharma in the company's acquisition by Alexion Pharmaceuticals, Inc.
  • Named a leading lawyer in Massachusetts in the 2022 edition of Who’s Who Legal: M&A and Governance.
  • Listed in The International Who's Who of Lawyers as one of the world's leading lawyers in the Life Sciences: Transactional, Corporate: Mergers and Acquisitions and Corporate: Corporate Governance practice areas.
  • Consistently recognized as a Massachusetts Super Lawyer for mergers and acquisitions, as well as for his representation of public companies.
  • Named to the Lawdragon 500 Leading Dealmakers in America list.

Insights & News


  • Education

    • JD, Suffolk University Law School, 1985

      magna cum laude Class Valedictorian; Editor, Suffolk University Law Review; Member, national championship team of the J. Braxton Craven Constitutional Law Moot Court Competition
    • BA, Brandeis University, 1982

      cum laude
  • Admissions

    • Massachusetts



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