Daniel Rosenthal

Daniel L. Rosenthal

Dan is a litigator with extensive experience in a broad range of business and commercial matters. Dan’s cases have involved too many areas of law and industries to list here, but they have included corporate fiduciary duties, implied warranties, franchise relationships, employment issues, railroad laws and practices, commercial leases, insurance coverage and constitutional issues — enough variety to keep him on his toes. Dan’s clients range from Fortune 500 companies to small businesses and individuals, and he has advocated for those clients in federal and state trial and appellate courts, as well as in administrative tribunals, arbitration and mediation.

A significant element of Dan’s practice is representation of automobile manufacturers in recurring franchise litigation with dealers.  Dan has also handled franchise and dealership issues in a number of other industries.

Before joining Marcus Clegg in 2010, Dan was a partner in a large Portland law firm, where he had practiced since 1998 and served as Chair of the firm’s Trial Department.  From 1997 to 1998, Dan served as a law clerk to then-Chief Judge Ronald R. Lagueux of the United States District Court for the District of Rhode Island.

Dan is the author of a chapter on discovery depositions in the volume, “A Practical Guide to Discovery and Depositions in Maine” (MCLE 2014), and he has served as a continuing legal education presenter on trial evidence and objections.  He also served as a member of the Civil Process Improvement Stakeholders Working Group created by the Maine Supreme Judicial Court to study and provide input on proposed changes to the Maine Rules of Civil Procedure.  He is rated “AV Preeminent” by Martindale-Hubbell, has been named a “Super Lawyer” and has been selected for inclusion in the Benchmark Litigation guide, which is based on interviews with attorneys and clients.


J.D., summa cum laude, Boston College Law School, 1997

A.B., cum laude, Bowdoin College, 1992

Admitted to Practice

  • Maine
  • Massachusetts
  • United States District Court for the District of Maine
  • United States District Court for the District of Massachusetts
  • United States Court of Appeals for the First Circuit

Contact Information

Daniel L. Rosenthal
Marcus Clegg
16 Middle Street, Unit 501
Portland, ME 04101
207-828-8000 (main)
207-210-6285 (direct)