A partner in the Litigation Department and former global co-chair of the Antitrust Practice Group, Aidan Synnott focuses on antitrust litigation and compliance, international arbitration, bankruptcy litigation and other complex commercial litigation. Clients have described Aidan as “an exceptionally incisive, efficient and precise lawyer,” who “has achieved exceptional results in the most difficult of circumstances.”

Aidan has extensive trial experience in state and federal courts as well as in alternative dispute resolution forums such as the LCIA, ICC, AAA and JAMS. In addition, he frequently represents clients in antitrust investigations by the governmental agencies of the United States and elsewhere.

Aidan’s antitrust litigation representations include:

The Nielsen Company, the leading provider of television ratings in the United States in winning summary judgment before the U.S. District Court for the Southern District of Florida, and confirming the victory on appeal to the U.S. Court of Appeals for the Eleventh Circuit, in a monopolization case brought by Sunbeam Television Corp., the FOX affiliate station in Miami. Sunbeam had claimed that Nielsen’s rollout of a new ratings measurement methodology was a violation of Section 2 of the Sherman Act. Sunbeam Television Corp. Nielsen Media Research, Inc., 763 F. Supp. 2d 1341 (S.D. Fl. 2011), aff’d, 711 F.3d 1264 (11th Cir. 2013);
Nomura Securities International, Inc. and Nomura Holdings, Inc., along with joint defense firms, in securing the dismissal, affirmed on appeal by the Second Circuit, of a consolidated class action alleging that Nomura and other major global financial institutions conspired to manipulate prices in the multitrillion-dollar global market for supranational, sub-sovereign and agency (SSA) bonds; Alaska Dep’t of Revenue, Treasury Div. v. Manku, No. 20‑1759‑CV, 2021 WL 3027170 (2d Cir. July 19, 2021);
Deutsche Bank in multi-regulator, multi-jurisdictional inquiries concerning the setting of numerous Interbank Offered Rates (IBORs) — the largest investigations ever faced by the bank — and in 50-plus individual and class actions concerning IBOR rates in multiple currencies;
The successful defense of Dun & Bradstreet, ACNielsen and IMS Inc. in a federal antitrust action brought by a large competitor, obtaining dismissal of the case on a pre-trial motion. Information Resources, Inc. Dun & Bradstreet Corp., 359 F. Supp.2d 307 (S.D.N.Y. 2004);
For the New York City Transit Authority, obtaining dismissal of a claim for attempted monopolization of the market for bus simulators. Doron Precision Systems, Inc. FAAC, Inc., 423 F. Supp.2d 173 (S.D.N.Y. 2006);
Acumen Brands, Inc., a leading retailer of western apparel, in obtaining dismissal, with prejudice, of a monopolization case brought by a competitor. Sell It Social, LLC Acumen Brands, Inc., 2015-1 Trade Cases P 79,114 (S.D.N.Y. 2015);
The defense of Sumitomo Chemical Company, one of the largest chemical companies in the world, in the vitamins price-fixing litigation. He has also defended numerous other U.S. and foreign companies in cartel cases; and
Pfizer Inc. in successful settlements of class and opt-out actions alleging $11 billion in damages for monopolization of the market for Neurontin, a Pfizer pharmaceutical, through an alleged pattern of meritless patent litigations.

Antitrust merger clearance and investigation representations Aidan has led include:

Continental Grain, a global investor, owner and operator of food and agribusiness companies, in its $4.5 billion acquisition, alongside global food corporation Cargill, of Sanderson Farms Inc;
IMG College, the collegiate division of Endeavor, in connection with the antitrust clearance process for its merger with Learfield Communications, bringing together two of sports’ largest multimedia rights and sponsorship businesses;
CDK Global, Inc., a supplier of dealer management software used to car dealerships, in connection with:
- its $8.3 billion all-cash acquisition by Brookfield Business Partners, Brookfield Asset Management’s flagship private equity vehicle;
- its proposed acquisition of Auto/Mate Dealership Systems; and
- its acquisition of ELEAD1ONE, a leading provider of fully integrated CRM software solutions to automotive dealers;
Time Warner Cable in successfully resolving the Justice Department’s Second Request investigation of its proposed $78 billion acquisition by Charter Communications as well as in the prior abandoned proposal by Comcast Corporation to acquire it for $45 billion;
Pace plc in a Justice Department Second Request investigation of its $2.1 billion acquisition by ARRIS Group Inc., where the Justice Department closed its investigation without imposing any conditions;
Automatic Data Processing, Inc.:
- in a Second Request investigation by the Justice Department of its $500 million acquisition of a payroll and tax outsourcing competitor, ProBusiness, where the Justice Department closed its investigation without imposing any conditions; and
- as lead antitrust and M&A counsel, it its acquisition of Celergo, an Illinois-based provider of global payroll management services;
Hewitt Associates Inc. in a Justice Department investigation of its proposed $4 billion acquisition by Aon, where the Justice Department closed its investigation without imposing any conditions;
Westcoast Energy in a Justice Department investigation of its $8 billion acquisition by Duke Energy, where the Justice Department closed its investigation without imposing any conditions;
The Nielsen Company in the FTC Second Request investigation of its proposed $1.25 billion acquisition of Arbitron, Inc., where the acquisition was approved in a consent decree which Aidan negotiated and which imposed minimal conditions;
Fidelity National Financial in the FTC Second Request investigation of its $3 billion acquisition of a title insurance competitor, Lender Processing Services, Inc., which was approved in a consent decree which Aidan negotiated and which required minimal divestitures; and
MGM in the FTC’s Second Request investigation of its acquisition by Amazon, where the FTC failed to challenge the transaction despite sending a close-at-your-peril letter.

Aidan’s recent bankruptcy representations include:

Revlon, in its succesful emergence from chapter 11 proceedings in the Southern District of New York;
Noranda Aluminum Holding Corp., a leading U.S. producer of primary aluminum foil products, and its wholly owned subsidiaries in their chapter 11 cases in the Eastern District of Missouri;
AbitibiBowater Inc. in its chapter 11 case in the District of Delaware;
Performance Sports Group in its chapter 11 case in the District of Delaware;
The Official Committee of Paragon Offshore plc, a U.K. offshore drilling company servicing oil and gas companies with operations in Brazil, Mexico, the North Sea, the Middle East, and elsewhere, in connection with Paragon’s chapter 11 case in the District of Delaware; and
PJT Partners, Inc. in collecting a bankruptcy fee in the chapter 11 case of Relativity Media in the Southern District of New York.

Aidan's International Arbitration experience includes, for:

A Japanese client, victory, after an LCIA five-day evidentiary hearing where Aidan was lead counsel, in a dispute with an Indian corporation in a dispute over the development of a phosphate mine in Peru; and
CFE, the Mexican electric authority, and its US subsidiary CFE International, victory, after an ICC five-day evidentiary hearing where Aidan was lead counsel, in an oil and gas dispute arising out of Winter Strom Uri, with WhiteWater Midstream, a Houston-based midstream provider. WhiteWater had filed the arbitration, seeking close to $200 million in damages for breach of contract. The Panel rejected all of WhiteWater’s claims and awarded CFE International over $30 million in damages, including 80% of its attorneys’ fees. White Water Midstream Logistics, LLC CFE International, LLC and Comision Federal de Electricidad, LCIA Arbitration No. 215223, Final Award (May 13, 2024).

Aidan’s commercial litigation representations include:

PJT Partners, Inc. in:
- securing the dismissal of a putative securities class action, Barrett PJT Partners Inc., 2017 WL 3995606 (S.D.N.Y. Sept. 8, 2017); and
- after several rounds of litigation in New York Courts, including two arguments in the New York Court of Appeals, settling a claim resulting from a fraud committed by a rogue employee;
A class of music publishers in their litigation against Napster, in which the publishers obtained an injunction against distribution of their musical works by Napster. The injunction was entered by the U.S. District Court for the Northern District of California and affirmed by the U.S. Court of Appeals for the Ninth Circuit. A&M Records, Inc. Napster, Inc., 284 F.3d 1091 (9th Cir. 2002);
A class of music publishers in the Grokster case, in which the music publishers ultimately prevailed before the U.S. Supreme Court. Metro Goldwyn Mayer Studios, Inc. Grokster, Inc., 125 S. Ct. 2764 (2005);
A class of music publishers in their litigations against MP3.com and Scour.net, both of which were settled favorably;
The National Music Publishers’ Association, Inc. (NMPA), the Songwriters Guild of America and the Nashville Songwriters Association International in a trial in the Library of Congress resulting in the setting of advantageous new rates and terms for the mechanical license under Section 115 of the Copyright Act;
The Nielsen Company in achieving the full dismissal and affirmance on appeal of multiple claims brought by New Delhi Television Company, an Indian broadcasting company, claiming corruption in the provision of TV ratings in India by a joint venture partly owned by Nielsen. Justice O. Peter Sherwood of the New York State Supreme Court granted Nielsen’s motion to dismiss in full from the bench at oral argument on the motion. New Delhi Television Ltd. Nielsen Holdings, N.V., 111 A.D.3d 437 (1st Dep’t 2013); and
Obtaining summary judgment and affirmance on appeal for the estate of a successful businessman in a lawsuit by the deceased’s former mistress alleging a right to large payments from the estate. In the Matter of Cheng Ching Wang, 114 A.D.3d 939 (2d Dep’t 2014).

Aidan is chair of the Antitrust and Trade Regulation Committee of the New York City Bar Association. Aidan is also a fellow of the American Bar Foundation and of the New York Bar Foundation. He has been an associate editor of the Antitrust Law Journal, a member of the Editorial Board of the American Bar Association’s Annual Review of Antitrust Law Developments, co-chair of the New York State Bar Association Section of Commercial and Federal Litigation’s Committee on Antitrust and a member of the Executive Committee of the Section. He currently serves on the Executive Committee of the State Bar’s Antitrust Section. Aidan has been a guest lecturer and speaker at New York University School of Law, The Wharton School and the University of Michigan Law School, and has published extensively in the areas of antitrust and intellectual property law. Aidan is the co-author of the “United States” chapter in the last several editions of The Public Competition Enforcement Review and served as General Editor of the Sixth through Sixteenth editions.

Aidan continues to be recognized by Chambers USA, The Legal 500, U.S News & World Report/Best Lawyers in America, Super Lawyers, the USA and International editions of “Who’s Who of Competition Lawyers & Economists” by Who’s Who Legal, and most recently, as one of the "Leading Litigators of America" and "Leading Global Litigators" by Lawdragon 500.