William M. Hannay represents corporations and individuals in civil and criminal matters involving federal and state antitrust law, the Foreign Corrupt Practices Act (FCPA), foreign direct investments (including Exon-Florio/CFIUS), antiboycott laws, export control regulations, Telephone Consumer Protection Act, and other unfair trade practices laws. He regularly assists foreign and domestic clients on the antitrust and Hart-Scott-Rodino Act aspects of mergers and acquisitions.

Bill has represented clients in many industries, particularly insurers and insurance support organizations in class actions brought against the insurance industry as well as natural gas and electric utilities in the public utility industry.

Previous Experience

Earlier in his career, Bill served with commendation in the United States Army during the Vietnam War (1967-1968). He has served as Chair of the American Bar Association’s 14,000-member Section of International Law and currently serves on the Board of Directors of the ABA’s Rule of Law Initiative (ROLI).

  • Experience

    • Bill is a former Assistant District Attorney in the New York District Attorney's Office. On behalf of Schiff Hardin clients, he has conducted non-public internal investigations and represented clients in external investigations by U.S. and foreign enforcement agencies.
    • For many years, Bill has been an Adjunct Professor at IIT/Chicago-Kent College of Law, teaching courses in Antitrust Law and International Business Transactions.
  • Credentials


    • Georgetown University Law Center, J.D., 1973
    • Yale University, B.A., 1966

    Bar Admissions

    • Illinois
    • New York
      • U.S. District Court for the Northern District of Illinois (Trial Bar)


          • Honorable Tom C. Clark, U.S. Supreme Court (1974-1975)
          • Honorable Myron H. Bright, U.S. Court of Appeals, Eighth Circuit (1973-1974)

          Professional Memberships

          • American Law Institute
          • Uniform Law Commission, Joint Editorial Board for International Law, Co-Chair
          • Union Internationale des Avocats (UIA), Rule of Law program, Director
        • Insights

          News Release

          2019 Leading Lawyers Lists Recognize 95 Schiff Attorneys

          Schiff Hardin LLP is pleased to have 95 attorneys named to the 2019 Leading Lawyers list.

          News Release

          Super Lawyers Names 39 Schiff Attorneys to 2019 Illinois Super Lawyers, Rising Stars Lists

          Two partners were recognized among “best of the best” on 2019 Illinois Top Lists


          Congress Enacts New Law to Control Foreign Investments in the U.S.

          President Trump signed into law the Foreign Investment Risk Review Modernization Act (FIRRMA) to modernize the CFIUS review process to address 21st century national security concerns today. Congress enacted FIRRMA as Title XVII of the Fiscal Year 2019 National Defense Authorization Act, HR 5515.

          News Release

          95 Schiff Hardin Lawyers Named to 2018 Leading Lawyers Lists

          Ninety-six Schiff Hardin lawyers have been named to the 2018 Leading Lawyers lists for Illinois and Michigan.


          DOJ Antitrust Division Again Emphasizes Risks of “No-Poach” Agreements

          In a recent speech, the head of the Antitrust Division of the U.S. Department of Justice (DOJ) once again warned companies about the antitrust risks of certain agreements among employers not to hire each other’s employees.


          New HSR Thresholds to Take Effect Soon

          On January 26, 2018, the Federal Trade Commission announced upward revisions to the jurisdictional thresholds for premerger notification filings under the Hart-Scott-Rodino (HSR) Act.

          News Release

          40 Attorneys Named to 2018 Illinois Super Lawyers, Rising Stars, and Top Women Lists

          Forty Schiff Hardin attorneys have been recognized on the 2018 Illinois Super Lawyers and Rising Stars lists.


          Supreme Court Decision in BMS Limits Where Companies Can Be Sued

          The U.S. Supreme Court’s decision delivered this week in Bristol-Myers Squibb v. Superior Court of California (BMS) reaffirmed the Court’s commitment to limiting state courts’ jurisdiction over national class actions.


          7th Circuit Affirms Summary Judgment for Dominant Illinois Hospital and its Exclusive Contracts

          Last fall, the dominant hospital in Peoria, Ill. won summary judgment against a claim of anticompetitive, exclusive dealing agreements made by its major competitor.


          Top 5 Antitrust Issues Facing Companies in the U.S. Today: #5 Intellectual Property

          Decades ago, antitrust enforcement officials developed the “9 No-No’s” regarding patents and licenses. The days of antitrust hostility toward intellectual property are behind us, but renewed tension between antitrust and intellectual property policy seems to be growing.

          Other Publications

          • Corporate Counsel’s Antitrust Deskbook (editor), Thomson/West Publishing (updated annually)
          • Corporate Counsel’s Guide to the Robinson-Patman Act (editor), Thomson/West Publishing (updated annually)
          • Corporate Counsel’s Guide to Relations with Competitors (editor), Thomson/West Publishing (updated annually)
          • Corporate Counsel’s Guide to Unfair Competition (editor), Thomson/West Publishing (updated annually)
          • Designing an Effective Antitrust Compliance Program, Volume 11, Corporate Compliance Series, Thomson/West Publishing (updated annually)
          • Designing an Effective FCPA and Anti-Bribery Compliance Program, Volume 12, Corporate Compliance Series, Thomson/West Publishing (updated annually)
          • Tying Arrangements: Practice Under Federal Antitrust, Patent and Banking Law (co-author), Bureau of National Affairs (updated annually)
          • Antitrust Counseling and Litigation Techniques (contributor), Matthew Bender (2011 – updated annually)
          • U.S. International Antitrust Enforcement: A Practical Guide to the Agencies’ 1995 Guidelines (co-author), Bureau of National Affairs (updated annually)
          • ABA Guide to Foreign Law Firms, Fifth Edition (co-editor), American Bar Association Section of International Law (2012)
          • Insurance Antitrust and Unfair Trade Practices Law (co-author), CCH (2006)
          • Insurance Antitrust Handbook (co-author), American Bar Association (2006)
          • A Lawyer’s Guide to Doing Business in South Africa (co-author/editor), American Bar Association (1996)
          • International Trade: Avoiding Criminal Risks, Butterworth Legal Publishers (1991)

        Energy and Environmental Law Adviser

        Natural Gas Act Does Not Pre-empt State Antitrust Laws

        Last week, the U. S. Supreme Court handed down an important decision on the jurisdictional reach of the Natural Gas Act (NGA).  The Court concluded that the NGA does not pre-empt a long-running group of state-law antitrust suits aimed at alleged misconduct by natural gas pipelines. In Oneok, Inc. et al. v. Learjet, Inc. et... Continue Reading