Experienced Trial, Antitrust, and Whistleblower Lawyers

WHAT WE DO

WORKING WITH YOU & FOR YOU

We’re a different kind of law firm. We apply our extensive legal knowledge and decades of experience. We work tirelessly for you from beginning to end. And together, we get results.

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Practice Groups

Antitrust Litigation & Counseling

Our attorneys are both experts in antitrust law and seasoned litigators. Our approach to every case, whether on the plaintiff’s side or the defense, is to be prepared to take the case to trial.

Whistleblower Representation

The Constantine LLP Whistleblower Lawyer Team has extensive experience representing whistleblowers under the qui tam provisions of the False Claims Act, the Dodd-Frank Act, the IRS Whistleblower Law, and the wide array of other federal and state whistleblower reward laws.

Commercial Litigation

Constantine LLP has broad experience representing plaintiffs and defendants in complex commercial litigations and arbitrations. Our reputation is built upon our central philosophy of aggressively and sensibly representing clients in all areas of commercial dispute.

Compliance, Monitoring & Investigations

Constantine LLP conducts efficient and effective internal reviews and investigations for its clients. We provide critical value by establishing the independence of investigations, a key issue both in seeking reduced penalties in criminal actions and in minimizing civil litigation exposure.

E-Discovery Counseling

Our e-discovery practice group, comprised of a dedicated team of attorneys, project managers, and legal technology specialists is at the forefront of e-discovery theory and practice. We work closely with our clients to tailor creative and flexible discovery plans that mitigate both costs and litigation risk.

Government Affairs

Constantine LLP has extensive experience representing clients before numerous federal and state agencies, including the Department of Justice, the Federal Trade Commission, the Federal Communications Commission, the Federal Reserve Bank, and the Attorney General of every state active in antitrust enforcement.

Intellectual Property & Technology

We represent high technology companies in the consumer electronics, software, internet, webcasting, retail, and reprographics industries in a variety of matters involving copyright, trademark, trade secret, and patent law. We regularly practice before federal district courts and courts of appeals, as well as arbitrations, administrative agencies and tribunals.

Offices

NewYork
New York
Constantine LLP

22 Vanderbilt Avenue
15th Floor
New York, NY 10017
T:212.350.2700

DC
Washington D.C.
Constantine LLP

700 12th Street NW
Suite 700
Washington, DC 20005  
T:202.204.3500

sanfrancisco
San Francisco
Constantine LLP

50 California Street
Suite 1500
San Francisco, CA 94111
T:415.639.4001

Latest News, Publications & Speeches

Sep32026
Three Constantine LLP Lawyers Recognized by Best Lawyers® in The Best Lawyers in America® 2027 Edition

By the Constantine LLP Team In August, the 2027 edition of The Best Lawyers in America® was released. We are pleased to announce that three Constantine...

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Jul202026
Constantine Cannon Partner Gordon Schnell Featured in NY Post Article On the Rise in High-Tech Healthcare Fraud by Organized Crime
Gordon Schnell

& the Constantine Cannon Whistleblower Team On July 13, the New York Post published an article on its investigation into the rise of healthcare fraud...

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Constantine LLP “can claim to have won two of the three largest antitrust settlements in U.S. history.” – Global Competition Review, 2012

Jun12026
Constantine Cannon Filed Amicus Brief on Behalf of Six Professors of Economics Supporting FTC’s Appeal in Case Against Meta

By the Constantine Cannon Antitrust Team In the FTC's appeal of the trial court's judgment for Meta Platforms, Ankur Kapoor and Ethan Litwin submitted an amicus...

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Constantine LLP Named National Tier-1 “Best Law Firm” for Antitrust Law and Antitrust Litigation – U.S. News Best Lawyers 2020

May52026
Constantine Cannon Wins Summary Judgment, then $14 Million Settlement for HDMI Licensing Administrator Inc. in License and Antitrust Dispute

By the Constantine Cannon Antitrust Team Constantine Cannon successfully defended the licensor of the HDMI interface technology, HDMI Licensing Administrator, Inc. (“HDMI LA”), against a...

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Constantine Cannon is now Constantine LLP