Image: Kenneth M Breen

Kenneth M Breen

Partner, Litigation Department
New York
200 Park Avenue
New York, NY
United States

Fax: 1(212) 230-7828


Ken Breen is a partner in the Litigation Department of Paul Hastings and, having recently completed a 10-year term as Global Chair of the Investigations and White Collar Defense practice, is now Head of the New York White Collar Defense practice.

Mr. Breen focuses his practice on regulatory enforcement and white collar criminal defense, internal corporate investigations and compliance advice. Mr. Breen defends corporations and executives in high-stakes investigations and trials involving a myriad of issues including securities fraud, consumer protection issues, money laundering, and anti-corruption allegations. Many of these matters involve law enforcement and regulatory agencies from multiple jurisdictions and cross-border legal issues. Mr. Breen regularly represents clients before the U.S. Department of Justice, the Securities and Exchange Commission, and other U.S., foreign, and state financial regulatory agencies and state Attorneys General offices. He has also appeared regularly in court over the last three decades, having tried 48 cases to verdict and argued multiple appeals. Mr. Breen has been selected to represent top clients from a broad range of industries, sectors, and regions around the world.

Mr. Breen is consistently recognized as a leading white collar defense and government investigations lawyer by Chambers USA, America's Leading Lawyers for Business. Chambers notes that Mr. Breen's clients hold him in "high esteem" and praise his "very shrewd mind," "exceptional legal vision," and "ability to look across the full spectrum of white-collar issues." According to Chambers, he impresses clients as "a very strong advocate," "an extremely clear thinker," "very focused, incredibly direct and also really strategic," "dedicated, tireless and [someone who] can quickly and effectively understand legal issues and the business needs of his clients," and "phenomenal - [….] very good at his craft and […] a great strategist." Clients also describe him as an "extraordinarily effective trial counsel" who "comes with the experience, gravitas and intellect" that lets the other side know that he will be "really prepared to try the matter."

Prior to private practice, Mr. Breen served as a federal prosecutor in the U.S. Attorney's Office for the Eastern District of New York, where he was Deputy Chief of the Business and Securities Fraud Section; prior to that, in the U.S. Department of Justice Tax Division.

Accolades and Recognitions

  • Recognized by Chambers USA for Litigation: White Collar Crime & Government Investigations (2010-2020).

  • Recognized by Legal 500 for Corporate Investigations & White Collar Criminal Defense.

  • Selected to the National Law Journal's "Trailblazers" list recognizing the nation's leading attorneys in criminal law.

  • Recognized as a "Legal Lion" by Law360 for securing a sentencing ruling without any period of incarceration in U.S. v. Connolly, et al. (S.D.N.Y.) (2019).

  • Noted as trial counsel in U.S. v. Connolly, et al. (S.D.N.Y.), shortlisted by Global Investigations Review (GIR) as "Most Important Case of the Year" for its impact on future government investigations (2019).


  • Mr. Breen received his B.A. in English from Boston College in 1989, and his J.D. from the Boston College School of Law in 1992, where he was Annotation Editor and Staff Writer for the Uniform Commercial Code Reporter Digest.


  • Mr. Breen is a member of the New York bar and is admitted to practice in the U.S. District Court for the Southern and Eastern Districts of New York and the U.S. Court of Appeals for the Second and Third Circuits.

Recent Representations

  • Represents public and private companies, real estate investment and development companies, and investment advisors in investigations by various U.S. Attorney's Offices, the DOJ, the SEC, the NY AG, and the NY Department of Financial Services.

  • Represents multiple FinTech apps in investigations by the CFPB, NY Department of Financial Services, and other state regulators on issues involving online lending, interest rates categorized as "tips," monthly memberships at lending companies, and other consumer fees.

  • Represented a Middle Eastern oil and gas company in large-scale and well-publicized FCPA investigations by the SEC and DOJ.

  • Represented a prominent proprietary trading firm and registered broker-dealer in the SEC v. Galleon Management, LP, et al., No. 09 Civ. 8811 (S.D.N.Y.) and SEC v. Cutillo, et al., No. 09 Civ. 9208 (S.D.N.Y.) insider trading cases.

  • Represented a major construction company in an EDNY U.S. Attorney's Office investigation of the company's billing practices, which was resolved by a deferred prosecution agreement.

  • Represented the Swiss banking operations of a major international bank as Independent Examiner in connection with a DOJ Tax Division Program offering Non-Prosecution Agreements for Swiss banks. 

  • Represented a multinational Latin American conglomerate with U.S. operations in connection with an internal audit committee investigation relating to accrual accounting issues and whistleblower allegations.

  • Represented an international financial services company in an investigation by the CFPB regarding its loan servicing platform and other technology services provided.

  • Conducted internal investigations for a leading state university system regarding various issues and issued public reports.

  • Represents and represented senior executives of leading international financial institutions and hedge funds in DOJ, SEC, CFTC, FCA, SFO, and Federal Reserve Bank investigations involving various issues.

  • Defended David Gibson (former CFO of Wilmington Trust) in an accounting fraud trial in the U.S. District Court for Delaware in 2018, U.S. v. Wilmington Trust Corp., et al., 16-CR-23 (D. Del.)(RGA), in his appeal in the Third Circuit Court of Appeals. Recently, the Third Circuit reversed all counts of conviction and the related SEC case was settled favorably. 

  • Defended Matt Connolly (former Deutsche Bank trading desk supervisor) in a LIBOR manipulation trial in the U.S. District Court for the SDNY in 2018, U.S. v. Matthew Connolly, et al., 16-CR-00370 (SDNY)(CM), and continues to represent Mr. Connolly in related proceedings.

  • Represented former New York City Police Commissioner Bernard Kerik in criminal cases in the Bronx and U.S. District Court for the SDNY.