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

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

Mary Anne handled 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 involved 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 was 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 had 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 served 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.
  • Represented 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.


Professional Activities and Memberships

  • 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