John M. Tanski
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John Tanski represents clients in sophisticated business disputes, focusing his practice on claims of trade secret theft, unfair trade practices, anticompetitive conduct, breach of contract, fraud and breach of fiduciary duty. Clients praise his “intellectual firepower” and describe him as “a valuable counselor to the business clients as they weigh the pros and cons of the possible paths to follow.”

John’s extensive litigation experience includes winning favorable results for clients in a variety of industries ranging from manufacturing and insurance to pharmaceuticals and software. He also has significant appellate experience in both federal and state courts across the country. Before entering private practice, he served as a law clerk to the Honorable Paul J. Kelly, Jr. of the United States Court of Appeals for the Tenth Circuit.

John is active in his community, serving as the Vice Chairman of the Glastonbury Water Pollution Control Authority and as a member of the Connecticut State Advisory Committee to the United States Commission on Civil Rights. He is a former member of the Commission on Connecticut’s Leadership in Corporation and Business Law and the Tenth Circuit’s Criminal Justice Act panel. His pro bono work has included representing inmates in civil rights lawsuits in federal district court and serving as a mediator in discrimination matters for the Connecticut Commission on Human Rights and Opportunities.

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Professional Activities

  • American Bar Association, Section of Litigation Law


  • In the United States District Court for the Eastern District of Michigan, currently represents multiple defendants in the Auto Parts antitrust class action MDL.
  • In the United States Court of Appeals for the Fourth Circuit, won unanimous affirmance of summary judgment defeating a nine-figure antitrust claim alleging that Stanley Black & Decker and other table saw manufacturers engaged in a group boycott of table saw safety technology.
  • In the United States District Court for the District of Connecticut, won summary judgment of no lost profits for Hubbell erasing a ten-figure trade secret damages claim relating to wireless lighting control systems.
  • In the Connecticut Supreme Court, successfully briefed an appeal on behalf of national insurance broker Brown & Brown, winning unanimous affirmance of summary judgment on all claims brought by Blumberg Associates Worldwide.  He previously briefed and argued the case successfully in the Connecticut Appellate Court.
  • In the United States District Court for the Western District of Washington, obtained a preliminary injunction for healthcare benefit and payment solutions provider WEX Health (formerly Evolution1) requiring benefits administrator Flex-Plan Services, Inc. to continue to perform the parties’ contract after Flex-Plan sued WEX Health seeking early termination.
  • In the United States District Court for the Southern District of New York, defeated an effort to dismiss claims for breach of contract, fraudulent transfer, successor liability, and declarations of intellectual property ownership and then served as the principal author of moving and reply briefs that obtained the dismissal of counterclaims seeking $3 million in damages against venture capitalist Joseph Harris and his company, Conestoga Capital Partners.
  • In the United States Court of Appeals for the Tenth Circuit, served as lead counsel in winning the unanimous reversal of Patricia Williams's two Travel Act sentences, resulting in her release after more than twenty-three years in federal prison. 
  • In the United States Court of Appeals for the Eleventh Circuit, co-authored a brief that won permission to take an interlocutory appeal of an order certifying a class for claims of false advertising against Mead Johnson, the maker of Enfamil LIPIL infant formula.  The Axinn team then persuaded the Judicial Panel on Multidistrict Litigation to transfer and consolidate similar class actions filed in districts across the country.  Later, John contributed to a successful effort to obtain court approval of nationwide settlement of the consolidated claims, and he co-authored a brief to the Eleventh Circuit that won unanimous affirmance of the settlement's approval.
  • In the Connecticut Superior Court’s Complex Litigation Docket, successfully briefed and argued in opposition to a motion to strike cross-claims of unjust enrichment and unfair trade practices arising from automotive parts remanufacturer Motorcar Parts of America’s purchase of assets from a failing competitor.
  • In the United States District Court for the Central District of California, co-authored a moving brief that won a temporary restraining order preventing Lego from blocking the import of construction toys by Canadian manufacturer Mega Brands.
  • In the United States District Court for the District of New Jersey, served on a trial team that obtained a favorable resolution for Actavis of patent infringement claims by Pfizer relating to the drug Gabapentin.  John’s work on the case included serving as a principal author of a brief that persuaded the district judge to reverse the magistrate judge’s order precluding key testimony by one of Actavis’s primary liability experts. 


Thought Leadership



  • JD – Columbia Law School (2006) Managing Editor, Columbia Journal of Transnational Law. James Kent Scholar. Harlan Fiske Stone Scholar. Simon H. Rifkind Prize. Lawrence S. Greenbaum Prize.
  • AB, cum laude – Princeton University (2003)


  • Connecticut
  • New York
  • US Court of Appeals for the Second Circuit
  • US Court of Appeals for the Fourth Circuit
  • US Court of Appeals for the Tenth Circuit
  • US District Court District of Connecticut
  • US District Court Southern District of New York
  • US District Court Eastern District of Michigan
  • US Supreme Court