Greg is chair of the firm’s Antitrust & Competition practice group and a nationally recognized trial lawyer in complex business litigation.

He has won victories for defendants and plaintiffs in some of Maine's largest cases and maintains a national and international litigation practice. He frequently advises overseas clients on U.S. legal matters. He is listed in Woodward/White's The Best Lawyers in America, which named him 2017 and 2015 "Lawyer of the Year" for Mass Tort Litigation/Class Actions - Defendants. He currently serves as court-appointed co-lead counsel for direct purchasers in In re Automotive Parts Antitrust Litigation, a series of private civil actions, with more than $200 million in partial settlements to date, that stem from the largest Department of Justice criminal antitrust investigation in U.S. history.

In other recent cases, he won a $19 million jury verdict as lead trial counsel in Missouri federal court in an international contract dispute, recognized in the National Law Journal as one of Top 100 Verdicts of the year; recovered $32 million for a class of direct purchasers of marine hose in federal antitrust litigation in Miami; and brought an antiterrorism case on behalf of American missionaries murdered in Colombia. He has argued five times before the U.S. Judicial Panel on Multidistrict Litigation.

Greg is experienced in class actions, antitrust & trade regulation, international, securities, construction, corporate, intellectual property, products liability, mass torts, contract, fraud, healthcare, RICO, employment, real estate, land use, technology, lender liability, professional malpractice, personal injury, wrongful death, fidelity & surety, insurance, arbitration and mediation.

Professional Activities

  • Vice Chair, American Bar Association Section of Antitrust Law Global Private Litigation Committee
  • Member, The Florida Bar, Antitrust & Trade Regulation Law Certification Committee

  • Participant, Gubernatorial Trade Mission to South Korea

  • Served as Chairman of The Florida Bar Convention
  • Former Member, Florida Bar Grievance Committee

Honors & Recognition

  • AV Preeminent™ rating by the Martindale-Hubbell® Law Directory
  • Listed in the Woodward/White's The Best Lawyers in America for Commercial Litigation, Litigation - Securities, Mass Tort Litigation / Class Actions - Defendants and Mass Tort Litigation / Class Actions - Plaintiffs
  • Recognized for Commercial Litigation in Chambers USA: America's Leading Lawyers for Business, which stated "Greg Hansel stands out for his prowess in relation to complex business litigation work. One interviewee also heralded him as 'a master of class action litigation.'"
  • Selected as a New England Super Lawyer in Antitrust Litigation, Business Litigation and Class Action/Mass Torts
  • Named a Litigation Star in Benchmark: Litigation, the Guide to America's Leading Litigation Firms and Attorneys
  • Board Certified in Antitrust and Trade Regulation Law by The Florida Bar
  • Board Certified in Business Litigation by The Florida Bar

Civic and Charitable Activities

  • Past Chairman of the Board and current Board Member, Community Financial Literacy
  • Regional Vice-Chair, and Member, Board of Directors, Lawyers' Committee for Civil Rights Under Law, Washington, D.C.
  • Chairman, Annual Giving in Northern New England for the University of Virginia School of Law
  • Member, Harvard Alumni Association Board of Directors
    • Regional Director, Harvard Clubs in Maine, New Hampshire, Vermont, and North/Central Massachusetts
    • Past President, Harvard Clubs in Maine and Tampa Bay (formerly West Coast Florida)
  • Member, Maine International Trade Center
  • Portland Rotary Club
  • Served on Executive Committee, Appalachian Mountain Club, Maine Chapter
  • Former Member, Board of Trustees, Portland Symphony Orchestra
  • Acted as pro bono attorney, Maine Equal Justice Partners
  • President, Cape Elizabeth Mock Trial Boosters

Publications and Presentations

  • "Extreme Litigation: An Interview with Judge Wm. Terrell Hodges, Chairman of the Judicial Panel on Multidistrict Litigation", Maine Bar Journal
  • Speaker, "Private Damages Actions: An International Perspective," ABA Section of Antitrust Law Spring Meeting
  • "Antitrust Class Certification After Hydrogen Peroxide" ABA Section of Antitrust Law Spring Meeting
  • "Dispute Resolution," author of Maine Chapter in international legal guide for corporate counsel, Getting the Deal Through, Law Business Research Ltd.
  • Speaker, "Betting-the-Company, How to Avoid and Survive High Stakes U.S. Litigation," Korea In-House Counsel Forum, program co-sponsored by U.S. Embassy, Seoul
  • Speaker, "Hot Topics in Class Actions," Annual Meeting of Maine State Bar Association
  • "Limiting Shareholder Class Actions: The Private Securities Litigation Reform Act of 1995," The Florida Bar Journal
  • "Strong Suit: A Primer on Class Actions," Mainebiz

Firm Highlights


Litigation and Arbitration Venue Provisions in Construction Contracts: When and How They Work

Venue and choice-of-law provisions are fairly standard in construction contacts, but can be overlooked due to their location within a contract. When drafted effectively, these provisions can help limit uncertainty about where and how...

Press Coverage

Maine State Police May Be Spying on You

Police and governments are increasingly turning to new tracking and monitoring methods in their efforts to prevent and record evidence of crimes. A Portland Press Herald investigation examines these expanding law enforcement abilities and the...


WC Alert: Recent Developments from Maine's Workers' Compensation Board

Frank A. Graf, MD, Reappointed to Approved List of § 312 Examiners At the February 11 meeting of the Maine Workers’ Compensation Board, Frank Graf, MD, was reappointed to the list of approved § 312...


The Potential of the Blockchain for Asset Protection Planning

While many legal scholars focus on the challenges and complications seemingly inherent to blockchain and cryptocurrency, others look past the fear and see potential. In this article for Cumberland Law Review , Ian Huyett and Brian Quirk...


Preti Flaherty Welcomes Government Relations Liaison Andrew I. Roth-Wells to the Firm

Preti Flaherty is pleased to announce that Andrew I. Roth-Wells has joined the firm as a Government Relations Liaison. Andrew will help manage legislative and regulatory advocacy efforts for the firm’s Government Affairs Team...


Preti Flaherty Attorney Benjamin S. Piper Promoted to Partner

Preti Flaherty is pleased to announce that the firm’s partnership has named attorney Benjamin S. Piper as a partner. Ben is a member of the firm's Environmental, Litigation, and Media Law Practice Groups and works...


David B. Van Slyke Named Preti Flaherty Managing Partner

Preti Flaherty is pleased to announce that, in a unanimous vote, the firm’s partnership has elected attorney David B. Van Slyke as its incoming Managing Partner. David is one of the preeminent environmental lawyers...


2020 Employment Breakfast Series: Strengthening Your Company's Management of Accommodation Requests

For more than 25 years, Preti Flaherty's Employment Law Group has been keeping clients, business partners, and friends up to date on recent developments in employment law. Join us as we continue that tradition...

Press Coverage

Bangor superintendent blocked BDN reporter on Twitter after critical news coverage

In an apparent violation of the First Amendment, Bangor schools superintendent Betsy Webb temporarily blocked a journalist on Twitter following a report that news of a student suicide was announced over the loudspeaker at...


2020 Employment Law Series: A Legislative Update for HR Professionals

For more than 25 years, Preti Flaherty's Employment Law Group has been keeping clients, business partners, and friends up to date on recent developments in employment law. Join us as we continue that tradition...