617.973.6147fax 617.367.2315



  • Harvard Law School, JD, 1972, cum laude
  • Harvard University, AB, 1969, cum laude

Donald H. Siegel, PC

617.973.6147fax 617.367.2315 V-card Download PDF

Donald Siegel is a founding member of our firm and was our managing partner from 1991 to 2000 and continues to serve on the firm’s Executive Committee.  He has practiced as a corporate lawyer for over 42 years and is the Senior Partner in our firm’s Corporate Department.  Don acts as a general counsel and advisor to corporate and other clients in a wide range of industries including software, internet consumer products, technology, telecommunications, retail and other industries representing both private business, venture capital and private equity backed companies and publicly traded entities.  Don’s practice focuses on middle market public and private company mergers and acquisitions where the consideration has involved cash, as well as publicly traded securities, representing venture backed companies with multiple classes of securities, ESOP participants and other complexities.

Representative Experience

  • Hayes Management Consulting in a management buyout through conversion to a limited liability company funded by senior and mezzanine debt from an institutional lender.
  • McKay Brothers, LLC and affiliates in formation, cross border transactions and investments from institutional clients.
  • Antaya Technology Corp. – sale of 100% of its stock to Delphi Industries for cash and an earnout.
  • iParty Corp. (NYSE MKT) in its recent merger with Party City Corporation in a $35 million transaction which the various series of preferred stock and common stock of iParty Corp. were exchanged for cash consideration.
  • National Rural Telecommunications Cooperative in its acquisition by merger of NeoNova Holding Company, an internet service provider company.
  • Infoscitex Corporation, a defense services contractor, in its merger with DCS Corporation, including participation in the transaction by the Company’s ESOP, and the spinoff of two subsidiaries.
  • Triumvirate Environmental, Inc. in the acquisition of the assets and real property of Chem-Tech Environnement located in Quebec Canada.
  • Schafer Corporation in its acquisition by MetalMark Capital and certain members of management, including the structuring and negotiation of the terms for Seller Senior Notes and Buyer subordinated debt financings.
  • National Dentex Corporation (NASDAQ) in its $120 million merger with GeoDigm Corporation, portfolio company of Welsh Carson Anderson & Stowe.
  • Hyaluron, Inc. – sale of 100% of its stock to Albany Molecular Research, Inc.
  • RKW SE in its acquisition of the capital stock of Danafilms, Inc. and its related real estate.
  • Isolation Technologies, Inc., a Massachusetts based manufacturer of advanced chromatography columns and hardware for the high-performance liquid chromatography market, in its sale of assets to Sapphire Engineering, Inc., a subsidiary of Idex Corporation.
  • Triumvirate Environmental, Inc. in its acquisition of assets of Perma-Fix of Maryland (waste disposal sites) and the stock and assets of the operating subsidiaries of GS Enviro-Services, Inc., an OTCBB company, involving a RCRA regulated TSD facility and an affiliated waste removal services business.
  • Lily Transportation Corp. in the sale of its Truck Leasing Division to Ryder Truck Rental, Inc.
  • National Rural Telecommunications Cooperative in various investments, including acquisitions and dispositions of investments in telecommunications companies, involving both minority and control positions.
  • The Holmes Group, Inc. and its principal shareholders in the structuring, negotiation and documentation of Holmes' merger into a subsidiary of Jarden Corporation.  This transaction was valued at approximately $625 million in cash and Jarden stock, a NYSE listed company.
  • The Holmes Group in its acquisition via merger of all the stock of The Rival Company, a NASDAQ listed company for approximately $130 million plus assumption of debt.
  • National Rural Telecommunications Cooperative in its participation with other investors in a $156 million strategic equity financing and a $200 million term loan financing and follow on debt and equity financings in WildBlue Communications, Inc.
  • Shawmut Design and Construction in the acquisition of its common stock to its ESOP and related financing transactions with Lasalle Bank, N.A.
  • Diversified Optical Products, Inc, (DiOP) in its $60 million stock sale to Axsys Technologies. DiOP is a leading supplier of high-end thermal surveillance cameras and lenses servicing the U.S. Border patrol, Air Force, CoastGuard and various Port Authorities.
  • iParty Corp. (AMEX; IPT) in its acquisition in a Chapter 11 proceeding of the assets and leases of The Big Party Corporation.
  • Intraserver Technologies in its $70 million stock merger with LSI Logic, Inc.
  • Commonwealth Venture Funding Group in various acquisitions, including Antaya Technologies, Inc., a cross-border acquisition of substantially all assets of Tectran Inc. and Tectran Mfg. Inc. and Carroll Engineering Co., together with related debt and equity offerings.
  • Profile Systems, Inc. in a stock merger with Comergent Technologies, Inc.
  • Lily Transportation Corporation and UNICCO Service Company in numerous debt financing transactions and asset acquisitions and dispositions.


Presenter, “A Practical Guide to Business Acquisitions”, MCLE, April 2010.
Panelist, "Roundtable: Inbound US M&A", Financier Worldwide Magazine, 2008
Presenter, “Representations, Warranties, Indemnification and Termination Clauses”, MCLE Seminar, 2008
Author of chapter “Conversion: Anti-Dilution Provisions”, Venture Capital Forms and Analysis, Law Journal Press, 2007
Speaker, “Video Leadership Seminars: Negotiating Acquisition Terms for Selling a VC-Backed Company”, ReedLogic, July 2006
Participation in drafting the National Venture Capital Association model financing documents, 2002-2006
Author of chapter on United States laws and practices in “Winning Legal Strategies -International Mergers & Acquisitions Law,” Aspatore Books, 2005

Don was named Massachusetts Super Lawyer every year from 2004 - 2016.

Outside Posternak

Trustee, Vice Chairman of the Board and Chair of the Capital Campaign, Massachusetts School of Professional Psychology
Member of the Board of the Overseers, Newton-Wellesley Hospital

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