McDermott Will & Emery (Chicago)

Katharine O’Connor

McDermott Will & Emery (Chicago)
Lawyer (Partner)

Katharine O’Connor focuses her practice on complex antitrust litigation, government investigations, defending mergers and acquisitions before antitrust enforcement agencies, and counseling clients on antitrust compliance issues. She has experience representing clients in a wide array of industries, including health care, manufacturing, food and finance Katharine is a member of the firm’s antitrust and competition practice, which has been designated a “Global Elite” practice, one of the top 25 in the world, by Global Competition Review each year since 2013. She has been recognized by Legal 500 US and Super Lawyers as excelling in the field of antitrust. Katharine has tried cases before juries, judges and arbitration panels, presented evidentiary hearings in federal and administrative courts, and argued before the US Court of Appeals for the Seventh Circuit, federal district courts and state courts. While in law school, Katharine was the managing articles editor of the University of Illinois Law Review and a legal extern to Magistrate Judge David G. Bernthal of the US District Court for the Central District of Illinois

Auteurs associés

McDermott Will & Emery (Paris)
McDermott Will & Emery (Los Angeles)
McDermott Will & Emery (Paris)
McDermott Will & Emery (Brussels)
McDermott Will & Emery (Brussels)


915 Bulletin

Katharine O’Connor, Ashley M. Fischer The US DoJ issues a second business review letter to show that it is still open to creative solutions to combat the COVID-19 pandemic and to get medical supplies where they are needed the most


The United States Department of Justice Antitrust Division (DOJ) has issued a second Business Review Letter pursuant to the expedited review process it announced on March 24, 2020 to review conduct related to COVID-19 within seven days. The letter released on April 20, 2020 issued to (...)

Ashley M. Fischer, Jon B. Dubrow, Katharine O’Connor The US DoJ publishes a business review letter to pharmaceutical and medical distributors in order to provide insights into the antitrust enforcer’s views on competitor collaborations and to improve product access to fight the COVID-19 pandemic


A recent business review letter issued by the US Department of Justice Antitrust Division to five pharmaceutical and medical/surgical distributors offers insights into the antitrust enforcers’ views on competitor collaborations aimed at improving product access to respond to the Coronavirus (...)

Katharine O’Connor The US District Court of the Southern District of Ohio grants three pretrial motions and dismisses the entire case with prejudice because of the fail to plea a rule of reason case in the hospital sector (The Medical Center at Elizabeth Place / Premier health)


District Judge Walter H. Rice of the Southern District of Ohio granted three pretrial motions brought by the Defendants on the eve of trial in The Medical Center at Elizabeth Place, LLC v. Premier Health Partners, et al., Case No. 3:12-cv-26, 2017 WL 3433131 (S.D. Ohio Aug. 9, 2017), and denied (...)

Katharine O’Connor, Gregory E. Heltzer The US FTC reaches settlement agreement with a company on the challenged professional association rules due to restriction of competition among its organist and choral conductor members (AGO)


The two current commissioners of the Federal Trade Commission (FTC) approved a final order and consent agreement with the American Guild of Organists (AGO) after a public comment period of two months. The FTC alleged that the AGO violated Section 5 of the Federal Trade Commission Act by (...)

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