Portrait of Mary Anne Mason


  • College of William & Mary, B.A.
  • Georgetown University Law Center, J.D.


  • District of Columbia
Mary Anne Mason, Partner Washington, D.C.
Phone: +1 202.624.2572
1001 Pennsylvania Avenue NW
Washington, DC 20004-2595

Mary Anne Mason is a partner in Crowell & Moring's Antitrust Group and resident in the firm's Washington, D.C. office. Mary Anne focuses on antitrust, competition and economic regulatory law. Her government investigations practice involves merger clearance and advice.

Mary Anne handles investigations and litigation matters related to price-fixing and anti-competitive conduct in several industries including the energy, life sciences, healthcare, consumer products and hospitality industries. Her government investigations practice involves merger clearance and advocacy for a diverse client base before the Department of Justice (DOJ), the Federal Trade Commission (FTC), the Commodity Futures Trading Commission (CFTC), and state attorneys general. Additionally, Mason is extremely knowledgeable across multiple sectors about federal regulations regarding market manipulation and Title VII provisions of the Dodd–Frank Wall Street Reform and Consumer Protection Act that impact over-the-counter commodity swaps markets. Mary Anne has a particular strength in energy markets working with clients on a wide range of economic regulatory policy issues, such as regulation of energy commodity derivatives and enforcement of market manipulation rules by the FTC, CFTC and FERC.

Mary Anne serves as pro bono counsel to the Maine Lobstermen's Association, an organization that supports a sustainable lobster resource and the traditional fishing communities that depend on it. She received her J.D. from Georgetown University Law Center and her B.A. from the College of William & Mary.

Representative Engagements

  • Hart-Scott-Rodino (HSR) counsel to TransCanada Pipeline Corporation in its successful acquisition of ANR Pipeline Company, ANR Storage Company, and Great Lakes Pipeline Company.
  • Represents energy and financial services firms on CFTC regulation of over-the-counter commodity derivatives markets covered by Dodd-Frank financial reform legislation.
  • HSR merger clearance counsel to several market-leading providers of renal dialysis services in proposed acquisitions of competing providers.
  • Represented a global market-leading producer of chocolate and sugar confections in CFTC investigation of market manipulation.
  • Antitrust and regulatory counsel to Southern California Edison Company in investigations of market manipulation, monopolization and attempted monopolization during the California energy crisis.
  • Represented a major national oil company in multi-district class action lawsuits alleging unlawful conspiracy to fix the prices of refined petroleum products through association with the Organization of Petroleum Exporting Countries.
  • Lead counsel for refiners and gasoline distributors in gasoline pricing investigations by federal and state antitrust authorities.
  • HSR counsel to Mobil Corporation in its merger with Exxon.
  • HSR counsel to major defense contractor in acquisition of provider of light armored vehicles.
  • Advised a global provider of nuclear power plant design, construction and operation services on global marketing joint venture with a major competitor.
  • Antitrust counsel to a major interstate pipeline on proposed joint venture arrangements with competitor to develop pipeline infrastructure.
  • Antitrust counsel to a major integrated electric utility on joint venture arrangements for development of electric power generating plant meant to deploy cutting edge renewable energy technology.
  • Antitrust and regulatory counsel to global franchisor of hotel brands.
  • HSR and antitrust counsel to a major producer and recycler of steel products in a multi-jurisdictional production and marketing joint venture.
  • Antitrust counsel to developer of revenue management products used by participants in the hospitality and travel industries.
  • Antitrust counsel to a global provider of hearing aid devices and related services.
  • Advise equity investors and customers in connection with merger investigations involving markets for oil and gas, petrochemicals, financial services, renal dialysis care centers, prescription benefit management services, geophysical survey services, software and networking services, and natural gas storage and processing services.
  • HSR counsel to a competing bidder in a hostile takeover effort of a firm with assets in immunohistochemistry markets.
  • HSR counsel to a purchaser of petroleum refinery divested pursuant to consent agreement with the FTC.
  • Represented global market-leading coal producer in Department of Justice investigation of alleged anticompetitive agreements.
  • Represented global market-leading coal producer in FTC investigations of potential merger between competitors.
  • HSR counsel to a competing bidder in a hostile takeover effort of a regional firm involved in linen and equipment rental services to the hospitality industry.
  • Represented Wal-Mart in defense of a class action lawsuit alleging unlawful price discrimination in the sale of prescription drugs.
  • Lead counsel for major consumers of coal in opposition to the proposed merger of Arch Coal and Triton Energy Company.


Admitted to practice: District of Columbia, Supreme Court of the United States, U.S. Court of Appeals for the Fourth, Fifth, Seventh, and Ninth Circuits

Leadership Positions

  • Vice-Chair – Committee on State Antitrust Enforcement, ABA Section of Antitrust Law
  • Past Chair and Vice-Chair – Committee on Fuels and Energy Industry, ABA Section of Antitrust Law
  • Past Vice-Chair – Committees on Unilateral Conduct, Exemptions and Immunities, and Public Service

Highlights, News & Knowledge

Speeches & Presentations

  • "Antitrust Update," ABA Antitrust Section Teleconference, sponsored by the Corporate Counseling Committee (May 2015). Presenters: Shawn R. Johnson, Chahira Solh, Mary Anne Mason, Sean-Paul Brankin, and Olivier Antoine.
  • "Surviving Antitrust Scrutiny of Non-HSR Reportable Transactions," Strafford Webinar (November 18, 2014). Presenter: Mary Anne Mason.
  • "AHIP & AHA Joint Discussion on the Changing Landscape of Healthcare Delivery," Crowell & Moring's Healthcare Ounce Of Prevention Seminar (HOOPS), Washington, D.C. (October 27-28, 2014). Speaker: Mary Anne Mason.
  • "Non-reportable Transactions," Strafford Publications Webinar (June 5, 2013). Speaker: Mary Anne Mason.
  • "Kinder Morgan-ElPaso Merger Review," Platts Energy Week TV (October 23, 2011). Interviewee: Mary Anne Mason.
  • "U.S. v. United Health Group, Inc.: Recent Antitrust Enforcement in Healthcare Markets," Unilateral Conduct Committee, ABA Section of Antitrust Law (October 2011). Speaker: Mary Anne Mason.
  • "Dodd-Frank Financial Reform: Implications for Energy Firms of Proposed CFTC Regulations," Houston Energy Conference (May 9, 2011). Speaker: Mary Anne Mason.
  • "Multijurisdictional Antitrust Enforcement and Remedies for Dominant Firm Conduct," Unilateral Conduct Committee, ABA Section of Antitrust Law (March 2008). Speaker: Mary Anne Mason.
  • "Competition Policy in Regulated Sectors," Oxford Competition Policy Conferences, Wadham College, Oxford, England (July 2, 2007). Speaker: Mary Anne Mason.
  • "Searching for Liability Standards under Section 2 of the Sherman Act," 2006 Spring Meeting, Section of Antitrust Law of the American Bar Association (April 2006). Speaker: Mary Anne Mason.
  • "Hot Topics in Section 2: News from the EC: 'Ubiquitous' Microsoft or Abuse of Dominance?" ABA Antitrust Section Spring Meeting (March 31, 2005). Speaker: Mary Anne Mason.
  • "Navigating Multijurisdictional Standards for Dominant Firm Conduct," Teleseminar for the American Bar Association (March 2, 2005). Speaker: Mary Anne Mason.


  • "What Every Lawyer Needs to Know About Antitrust Enforcement, Post-ACA," AHLA Connections (November 2016). Authors: Megan L. Wolf, Joseph M. Miller, and Mary Anne Mason.
  • 2015 Antitrust M&A Year in Review (January 2016). Co-Authors: Wm. Randolph Smith, Olivier N. Antoine, Sean-Paul Brankin, Dr. Salomé Cisnal de Ugarte, Thomas De Meese, Shawn R. Johnson, Lisa Kimmel, Arthur N. Lerner, Mary Anne Mason, Joseph M. Miller, Jeane A. Thomas, Ryan C. Tisch, and Michael G. Van Arsdall.
  • Regulatory Forecast 2016: What Corporate Counsel Need to Know for the Coming Year (January 2016). Contributor.
  • Antitrust — Healthcare Industry in the Spotlight (January 2016). Contributors: Mary Anne Mason and Shawn R. Johnson. Also published in Westlaw Journal's Antitrust Report.
  • FTC Will Not Shy Away From Vertical Theories Of Harm (April 28, 2015). Authors: Mary Anne Mason and Mika Clark.
  • 4 Antitrust Tips For Bidding On Land For O&G Production (December 12, 2014). Co-Authors: Joshua Stokes, Mary Anne Mason, and Beatrice B. Nguyen.
  • Navigating the System: Here Are Tips on How to Best Handle Market Manipulation Enforcement (Fall 2014). Co-Authors: Mary Anne Mason and Michael G. Van Arsdall.
  • Considerations and Strategies in Non-HSR Reportable Transaction (February 22, 2013). Author: Mary Anne Mason.
  • Corporate Transactions and Merger Control (February 16, 2012). Author: Mary Anne Mason.
  • CFTC Issues Final Dodd-Frank Anti-Manipulation Rule (July 13, 2011). Author: Mary Anne Mason.
  • The CFTC Proposes Exemptive Relief Regarding Effective Dates for Certain Dodd-Frank Act Provisions and Announces Additional Rulemaking Meetings (June 20, 2011). Author: Mary Anne Mason.
  • Business Justification Defense (May 19, 2011). Author: Mary Anne Mason.
  • Summary of the CFTC and SEC Joint Proposed Rules Regarding Product Definitions (May 18, 2011). Author: Mary Anne Mason.
  • CFTC Issues Proposed Rule Regarding Reporting and Recordkeeping for Pre-Enactment and Transition Swaps (May 5, 2011). Author: Mary Anne Mason.
  • CFTC Issues Proposed Rules on the Definition of 'Swap' and on Capital Requirements for Swap Dealers and Major Swap Participants (April 28, 2011). Author: Mary Anne Mason.
  • Energy Industry Prepares for CFTC Rulemakings and 'Robust Oversight' in Swap (September 7, 2010). Author: Mary Anne Mason.
  • Financial Reform Legislation Impacts the Energy Industry (July 23, 2010). Author: Mary Anne Mason.
  • Certain Financial Hedge Arrangements Can Violate Sherman Act Section 1 (June 25, 2010). Author: Mary Anne Mason.
  • American Needle: The Supreme Court Evaluates Antitrust Immunity for Joint Ventures (June 15, 2010). Author: Mary Anne Mason.
  • Business Justification Defense (2008). Author: Mary Anne Mason.
  • The 'Trinko' Decision (February 16, 2004). Author: Mary Anne Mason.
  • Energy Antitrust Handbook (2000). Editor: Mary Anne Mason.

Client Alerts & Newsletters

In the News

Firm News & Announcements

Jan.22.2015 Crowell & Moring's Antitrust Group Featured in Global Competition Review's 15th Edition "GCR 100"
Jun.24.2013 Crowell & Moring Expands Antitrust Group, Strengthens Energy Markets Bench
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