Mark Rosen represents clients in high-stakes business litigation and provides counseling on complex legal challenges. Mark focuses on commercial and class action litigation as well as matters of corporate governance. He represents companies and financial services firms in class action litigation, securities litigation, and complex business litigation including breach of contract and breach of fiduciary duty actions arising out of commercial transactions, mergers & acquisitions, privatizations and financings.  Mark has extensive experience in shareholder disputes involving public and private companies, closely-held corporations, controlling stockholders and alternative entities, including application of the business judgment rule.

Mark also represents companies and individuals in trade secrets, competition and employment litigation, including claims of misappropriation of trade secrets and breach of non-compete and confidentiality agreements.  He defends banks and financial institutions in tort and contract actions involving check fraud, bank operations and a variety of UCC issues.

In addition to his litigation practice, Mark counsels clients on corporate governance matters, including the fiduciary duties of directors, officers and managers, disclosure obligations, regulatory compliance, insider trading issues and ways to minimize litigation exposure. He has conducted internal investigations on behalf of boards of directors, audit committees and companies. Mark also represents companies and individuals in SEC investigations. Before joining Pierce Atwood in 2010, Mark practiced in the Securities Litigation and Corporate Governance Group at Weil, Gotshal & Manges LLP in New York.

Professional Activities

Member, New Hampshire Bar Association

Civic Activities

  • Treasurer, Board of Directors, Tenants Association at Pease, Inc.
  • Secretary, Board of Directors, Brixham Montessori Friends School
  • Pro bono counsel for underserved clients referred by the New Hampshire Legal Advice and Referral Center

Practice Areas

Representative Experience

  • M&A and shareholder litigation: Recently represented a public target company in the high-tech and energy sectors and its board of directors in a shareholder class action alleging breach of fiduciary duties and related disclosure violations in the approval of a merger transaction. Defended the company and its directors through expedited discovery and injunction proceedings, and successfully negotiated a favorable disclosure-only settlement that allowed the transaction to close as scheduled.
  • Recently represented a public company acquirer in a shareholder class action alleging aiding and abetting breach of fiduciary duties in the approval of a merger transaction, defeating the plaintiff’s motion for preliminary injunction and obtaining dismissal of the claims against his client.
  • Successfully represented a medical devices company and its board of directors in a shareholder challenge to the company’s preferred stock financing.
  • Government investigations:  Recently represented the former controller of a large New England ski resort in an SEC investigation into the resort’s use and accounting of capital funds obtained through two private offerings. Also represents institutional and individual clients in insider trading investigations. 
  • Shareholder securities fraud class actions: In 2012-13, successfully defended a New Hampshire public company in a Rule 10b-5 class action alleging misrepresentations and omissions in the company’s SEC filings. In 2010, represented private real estate partnerships and their principals in a securities fraud suit brought by limited partner investors. In a complete victory, won dismissal, with prejudice, of the complaint's federal securities and state-law breach of fiduciary duty claims.
  • Consumer class actions: Defended an internet marketing company in a consumer fraud class action and obtained summary judgment in favor of the defendants.
  • Construction Litigation:  Represents owners and contractors in construction disputes and litigation concerning complex commercial projects and the award of government contracts.