Brian Massengill focuses his practice on the intersection of litigation with accounting and finance issues. He is the co-leader of the firm’s Professional Liability practice group.
Brian brings his background as a Certified Public Accountant, including eight years with a national accounting firm, to bear on his legal work. His practice focuses on the defense of accounting firms and he has represented firms in a variety of matters including securities class actions, SEC and PCAOB investigations, arbitrations, and state accountancy board proceedings.
Brian’s combined legal and accounting experience also enables him to serve clients in a variety of other contexts relating to mergers and acquisitions. He has represented companies in disputes arising from purchases and sales of businesses, including purchase price (post-closing adjustment) disputes, suits alleging breaches of representations and warranties, and suits alleging breaches of fiduciary duties. He also has represented companies in SEC and other regulatory investigations, and contract and other disputes involving complex causation and damages issues. As part of his litigation practice, Brian has worked extensively with experts in the areas of auditing, accounting, causation and damages.
Prior to joining Mayer Brown in 1996, he was Law Clerk to The Honorable Frank H. Easterbrook, US Court of Appeals for the Seventh Circuit.
- Represent LKCM and affiliates in suit alleging breaches of fiduciary duty relating to the acquisition of certain portfolio companies in Delaware Chancery Court.
- Represent TC Energy in securities class action, and fiduciary duty and appraisal actions in Delaware Chancery Court.
- Represented TC Energy in breach of representation and warranty litigation relating to the sale of assets to Helix Generation in Delaware Superior Court.
- Represented Moore Stephens Hong Kong in securities class action litigation and regulatory investigations relating to Puda Coal, Inc.
- Represented Nestle Purina PetCare Company in suit relating to breaches of representations and warranties by sellers of Merrick PetCare Holdings in Delaware Chancery Court, and related working capital dispute.
- Represented accounting firms and their audit partners in SEC and PCAOB investigations.
- Represented Ernst & Young LLP in a series of matters concerning Bally Total Fitness, including the SEC investigation, securities class action and shareholder derivative suit.
- Represented PricewaterhouseCoopers International in matters relating to Satyam Computer Services Ltd.
- Represented public companies in SEC and other regulatory investigations.
- Successfully represented Ernst & Young LLP in a series of matters arising out of the bankruptcy of Asche Transportation Services, including obtaining dismissal of a securities class action and judgment for the firm after a lengthy arbitration hearing.
- Successfully represented clients in purchase price arbitrations and matters involving assertions of breaches of representations and warranties in M&A transactions. These include the representation of a Fortune 100 company in a dispute relating to its $800 million acquisition of a manufacturing company; the representation of a privately held company in a post-closing adjustment arbitration relating to the sale of a major appliance manufacturer; the representation of the sellers of a construction company in a post-closing adjustment arbitration and related allegations of breaches of representations and warranties; representation of the seller of an airline catering business in a post-closing adjustment arbitration; and the representation of the seller of a members-only manufacturer direct-buying company in a post-closing adjustment arbitration.
- Represented a domestic manufacturer in an international arbitration relating to a contract dispute with a supplier involving complex damages issues.
The University of Chicago Law School, JD
University of Chicago Law Review
Registered Certified Public Accountant (CPA), Illinois
Indiana University, BS in Accounting
- Nueva York
- US Court of Appeals for the Second Circuit
- US Court of Appeals for the Third Circuit
- US Court of Appeals for the Seventh Circuit
- US District Court for the Northern District of Illinois
- US District Court for the Southern District of New York