O’Melveny Worldwide

Ben Hallmark focuses his practice on administrative law and litigation matters, including contested cases before state agencies such as the Public Utility Commission of Texas and the Railroad Commission of Texas. He has represented clients in a wide range of litigation matters involving energy issues, deceptive trade practice claims, trade secrets, and other complex commercial issues. Ben has also handled appeals in the Texas Supreme Court and various Texas Courts of Appeals.

  • Recurring representation of a consortium of more than 40 Fortune 500 companies with large Texas operations on contested matters before the Public Utility Commission, Texas Courts of Appeals, and Supreme Court of Texas
  • Represented a consortium of more than 40 Fortune 500 companies with large Texas operations in ratemaking proceedings before the Texas Railroad Commission
  • Represented clients in contested pipeline rate matters before the Texas Railroad Commission
  • Obtained dismissal of Texas Deceptive Trade Practices Act claim against Retail Electric Provider
  • Represented clients on various Texas Public Information Act matters
  • Represented a large electrical cooperative in a breach of contract case against an electricity supplier


Bar Admissions

  • Texas

Court Admissions

  • US Court of Appeals, Fifth Circuit
  • US District Court, Northern District of Texas


  • The University of Texas School of Law, J.D., 2009, with high honors: Texas Law Review, Chief Notes Editor (2008-09); Legal Research Board; Order of the Coif
  • The University of Texas at Austin, B.A., 2000

Honors & Awards

  • Recognized by Chambers USA in the category of Energy: State Regulatory & Litigation, Electricity (2020, 2022-2023)
  • Recognized by Best Lawyers® for Administrative/Regulatory and Energy Regulatory Law in Austin, TX (2022-2024); Ben has been listed in Best Lawyers® since 2019
  • Recommended Attorney, The Legal 500 US (Industry Focus: Energy Regulatory), 2019

Professional Activities


  • The Honorable Nancy F. Atlas, US District Court, Southern District of Texas (2009-2010)


  • State Bar of Texas; Public Utility Law Section
  • Austin Bar Association


  • Presenting Effective Arguments in Administrative Proceedings,” 15th Annual Advanced Texas Administrative Law Seminar, UT Law CLE (September 2020)
  • Cross-examination in Administrative Hearings,” Austin Bar Association’s Anatomy of an Administrative Hearing (March 2016)