Warren B. Rosenbaum


Warren B. Rosenbaum



Direct: 585-987-2813
Fax: 585-445-2313


At a Glance

Warren B. Rosenbaum is a Partner and a member of the Litigation Department. He concentrates his practice in corporate, commercial, fiduciary, creditor's rights, bankruptcy, and land use litigation, as well as general corporate and business law.

Mr. Rosenbaum has long served as lead litigation counsel in a variety of large and complex legal matters in Federal, Bankruptcy and State Courts, including representation of publicly-traded and privately held business organizations and shareholders in the prosecution and defense of shareholder derivative, shareholder fair value merger disputes, and breach of fiduciary cases. He has also served as lead counsel for the Trustee in securities fraud litigation, for the municipality in Federal and State Court litigation, as attorney for the former owners of Midtown Plaza in both State and Bankruptcy Court litigation, as attorney for the Receiver in a number of cases, including that involving dissolution and liquidation of the assets of a regional hospital, and for the developers in contested land use matters.



    • Named Lawyer of the Year for Litigation- Bankruptcy in Rochester in 2021 by "Best Lawyers in America."
    • Consistently named by "Best Lawyers in America" in the categories of Bet-the-Company Litigation, Commercial Litigation, Banking and Finance Litigation, Bankruptcy Litigation, Mergers and Acquisitions Litigation, and Real Estate Litigation

Industry Expertise


University of Buffalo Law School, J.D.

University of Toledo, B.B.A.

Bar Admissions

  • State of New York
  • United States District Court, Western, Northern and Southern Districts of New York
  • United States Bankruptcy Court, Western and Northern Districts of New York
  • United States Court of Appeals, Second Circuit 
  • United States Tax Court
  • United States Court of Federal Claims

Key Representative Matters

  • Lead counsel for the Trustee in large, complex securities fraud case in both U.S. District and Bankruptcy Courts involving multiple parties, recovering millions of dollars in assets for defrauded investors and other creditors.
  • Lead counsel for Court-appointed Receiver of a large, regional not-for-profit hospital in liquidation of assets, recovering millions of dollars in funds for the benefit of creditors and resolving disputed issues of asset ownership and lien priorities through litigation.
  • Lead counsel for large group of investors in U.S. District Court-based securities fraud litigation recovering virtually all of the investors' losses against large, multinational insurance carrier which had promoted the investments.
  • Successfully represented multi-national business outsourcing company in multiple unfair competition actions in state and federal courts.
  • As lead counsel represented publicly-traded technology company in patent licensing dispute, winning dispute concerning ownership of patent rights. 
  • Lead counsel for publicly-traded corporation in obtaining dismissal of shareholder derivative action
  • Lead counsel for minority members of large regional dairy farm in successfully concluding litigation concerning alleged forced termination of membership interests.
  • Lead counsel for minority shareholders in successfully concluding litigation concerning allegations of minority shareholder oppression and breach of fiduciary duties against board of directors and majority shareholder
  • Lead counsel for family of deceased husband in obtaining reversal of adverse judgment through appeal to state's highest appellate tribunal resulting in recovery for family of substantial six-figure award from annuity company.
  • As lead counsel, successfully represented large, regional accounting firm in arbitration of dispute with former partner who had been expelled from the firm.
  • Lead counsel for national securities brokerage firm in obtaining victory in securities arbitration in dispute with a major national banking institution over charges of raiding of brokerage business.
  • Lead counsel for owners and operators of large shopping mall in litigation with City, with major tenant and in creditor work-out matters through successfully-concluded Chapter 11 bankruptcy proceedings.
  • Lead counsel for municipality in civil rights, contract and tax-payer actions over conversion of municipal water system to county water authority.
  • Lead counsel for developers of new regional shopping center in successful defense of multi-prong litigation aimed at halting development
  • Lead counsel for secured lenders in Chapters 11, 12 and 13 bankruptcy proceedings in Western and Northern Districts of New York Bankruptcy Courts.

Professional Affiliations

  • Member of the Monroe County Bar Association, Chair of the Judiciary Committee and past member of the Board of Trustees.
  • Member of the New York State Bar Association and its Commercial and Federal Litigation Section.