Gregg M. Mashberg - Proskauer Rose LLP

Gregg M. Mashberg

Listed in Best Lawyers since 2010
Phone: 212-969-3450


Gregg Mashberg is co-head of the Securities Litigation & Enforcement Group and a former Chair of the Litigation & Dispute Resolution Department. He has a broad-based practice and experience before numerous judicial and administrative forums.

Gregg has a particular focus on securities litigation, defending public companies and their directors and officers in class actions, SEC investigations and enforcement actions. Gregg also has broad experience in defending directors and officers in shareholder derivative actions and direct breach of fiduciary duty suits under state law.

As part of his securities litigation practice, Gregg is outside litigation counsel for The Depository Trust & Clearing Corporation and its subsidiaries, the nation's principal securities settlement and depository institutions. He has litigated in trial and appellate courts around the country, successfully defending against claims challenging the securities clearing and settlement system.

Gregg also has substantial litigation experience involving core aspects of Proskauer’s litigation practice, including general commercial disputes, antitrust, bankruptcy, entertainment, sports, First Amendment and trade secrets. He recently won summary judgment in a commercial dispute on behalf of a major British company, dismissing a complaint seeking $100 million in damages. Gregg is an experienced courtroom lawyer; for example, he won a $3 million federal jury verdict in a stockholders’ derivative action in a case involving the closing of a Wall Street brokerage house.

Following law school, Gregg spent five years in the New York City Corporation Counsel's Office, becoming an Assistant Chief of the General Litigation Division. In that position, Gregg was lead counsel for the City in major institutional change class actions. He also represented the City in litigation concerning significant public policy disputes.

Since entering private practice, Gregg has maintained his interest in public law, most recently serving as lead counsel to the Metropolitan Transportation Authority in successfully defending against challenges to the MTA’s 2003 decision to raise fares and tolls in the amount of $900 million.


Case History

N.Y. Pub. Interest Research Group Straphangers Campaign, Inc. v. Metro. Transp. Auth., 309 A.D.2d 127; 763 N.Y.S.2d 13 (NY 1st Dep''t 2003) — Represented New York''s Metropolitan Transportation Authority in defending decision to raise subway fares and tolls in the amount of $900 million.  Appellate court reversed trial court and unanimously ruled to dismiss the challenge and upheld the agency''s actions.
ARZOOMANIAN v. BRITISH TELECOMMUNICATIONS, PLC., 2007 U.S. Dist. LEXIS 2715 (D.N.J) — Represented British Telecom in defending claim for $100 million in damages in connection with claimed brokering of one of the largest if not the largest telecommunications outsourcing agreements as of that time.  Complaint dismissed on summary judgment.
Pet Quarters, Inc. v. Depository Trust & Clearing Corporation, 559 F.3d 772 (8th Cir. 2009) — I represented defendant DTCC, the organization that clears and settles the nation''''s securiteis transactions.  8th Circuit upheld dismissal of complaint, establishing that challenges to rules adopted by a self-regulatory organization that had been approved by the SEC were not justiciable under the conflicts preemption doctrine.  We prevailed in similar cases around the country, e.g. Nanopierce Technologies, Inc. v. Depository Trust & Clearing Corporation, 168 P.3d 7 (Sup. Ct. Nev. 2007); Whistler Investments, Inc. v. Depository Trust & Clearing Corporation, 539 F.3d 115 (9th Cir. 2008).

Client Comments

"Gregg's knowledge in both areas of commercial litigation and securities litigation comes from experience of cases at all levels and a very good understanding of what the client needs to achieve. He has guided us on achieving our requirements always with a pleasant manner. He really gets into the detail of a case. I would highly recommend him to other heads of litigation for FTSE 100 companies."

-Miles Jobling
Head of Litigation
British Telecommunications plc

Office Location

Eleven Times Square
New York, NY 10036-8299
United States

Practice Areas

Commercial Litigation
Litigation - Mergers and Acquisitions
Litigation - Securities

Other Information

Gender: Male