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  1. Professionals

LeElle B. Slifer

Partner

Co-Chair, General Litigation Practice

Dallas

+1 214-453-6431

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  • Overview
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LeElle is an experienced trial lawyer who serves as co-chair of Winston’s General Litigation Practice. Her clients describe her as a litigator who “provides time-critical business and strategic counsel that can make all the difference in high-stakes litigation.” With significant experience in a wide range of disputes—including complex commercial, breach of contract, oil and gas, breach of fiduciary duty, antitrust, patent and copyright infringement, non-competes, theft of trade secrets, class actions, and even the seizure of cargo barges and private jets—LeElle can efficiently and strategically tackle any issue. LeElle understands that getting the best result for her clients means more than just the legal outcome, it means keeping the client’s business goals in mind every step of the way.

LeElle has litigated in federal and state courts nationwide, trying matters before both judges and juries. She has participated in numerous domestic and foreign arbitrations, including before the International Chamber of Commerce (ICC) in London. One of her trials—DDR Holdings v. Hotels.com, in which her team won a jury verdict of patent infringement in the Eastern District of Texas—was the first case to survive a Section 101 challenge at the Federal Circuit after the Supreme Court issued Alice Corp. v. CLS Bank Int’l and was the only case to do so for almost two years.

She has handled appeals to several federal and state courts of appeal, including the Supreme Court in Comcast Corp. v. Behrend.

LeElle knows that litigation forms just one aspect of her clients’ businesses. She thinks tactically, keeping her clients’ objectives and concerns top-of-mind as she counsels them through litigation. And her clients can attest to the success of LeElle’s results-oriented approach:

“I have had the privilege to work with some of the brightest and most highly regarded lawyers in the country. LeElle is in that class. She is a brilliant strategist, master negotiator, and has the wisdom and discipline to know how and when to use honey or vinegar, both of which she does very effectively. LeElle is dogged in her pursuit of the issues and is as comfortable on Wall Street as she is in a small rural courthouse—a rare skill set indeed. I would not hesitate to recommend LeElle to anyone who needs strong, creative, and efficient counsel for important litigation or other dispute resolution matters.” – Andy Fletcher, General Counsel for Stonebriar Commercial Finance.

Key Matters

Some of the experience represented below may have been handled at a previous firm.

LeElle’s representative experience includes:

  • Kosmos Energy Sao Tome and Principe v. ERHC Energy (BVI) Limited (International Chamber of Commerce (London); Harris County District Court, Texas 157thJudicial District) – Represented Kosmos in a dispute over rights to conduct oil and gas exploration in the Exclusive Economic Zone off the coast of São Tomé and Príncipe. Oversaw dual-track litigation in the ICC and Harris County. Secured preliminary injunctions in both jurisdictions, summary judgment on liability in Harris County, and a complete victory at the ICC, including attorneys’ fees.
  • Torreya Partners LLC v. [Confidential] (American Arbitration Association) – Represented a pharmaceutical marketing firm in a dispute with a pharmaceutical manufacturing company over fees owed under a marketing agreement. After taking over for prior counsel within six months of arbitration, finalized a settlement two days before trial that far exceeded the client’s desired result.
  • Pizza Hut Inc. v. Accenture LLP (S.D.N.Y.) – Represented Pizza Hut in a breach of contract action against Accenture for failure to provide a software product. Filed suit immediately after pre-suit mediations ended at an impasse. The very next day, Accenture acceded to settlement demands and the parties executed a final agreement within four months. Obtained a settlement of the entire dispute with nothing more than filing a complaint.
  • DDR Holdings, LLC v. Hotels.com, L.P., et al. (E.D.T.X.) – Represented inventors and patent holders in a patent infringement suit against seven defendants involving third-party website design features. After a jury trial, won verdicts of infringement against the only two defendants who had not settled. Successfully defended the verdict on appeal to the Federal Circuit on a § 101 challenge—the first case to do so after the Supreme Court issued Alice Corp. v. CLS Bank Int’l.
  • Stonebriar Commercial Finance v. Zetta Jet et al. (Collin County District Court, Texas 380thJudicial District) – Won complete judgements (including award of attorneys’ fees) against defendants and then pursued enforcement actions in five different states including managing several related actions in Colorado state court and bankruptcy court. Negotiated the exchange of a private aircraft as part of the settlement agreement.
  • Stonebriar Commercial Finance v. Griffin Barges (S.D.T.X. and E.D.L.A.) – Seized four multimillion-dollar cargo barges (two in the Houston Ship Channel, two docked in New Orleans) used as collateral to secure a loan. Facilitated the subsequent sale of the barges, the proceeds of which fully covered the entire outstanding debt, and all attorneys’ fees.
  • Black Stone Minerals v. Chesapeake, PXP Louisiana, et al. (DeSoto Parish, Louisiana 42ndJudicial District) – Sued Chesapeake and PXP Louisiana (now Freeport-McMoRan) for underpaying royalties on minerals produced in the Haynesville Shale. Reached a favorable settlement with PXP within months of filing suit and with Chesapeake days before trial.
  • Black Stone Minerals v. Chesapeake, Total E&P, et al. (part of MDL in Tarrant County District Court, Texas 348thJudicial District) – Sued Chesapeake and Total for underpaying royalties on minerals produced in the Barnett Shale as part of the leadership in multidistrict litigation in Texas involving similar claims made by other royalty owners. Briefed, argued, and defeated multiple case-specific and MDL-wide summary judgment motions which resulted in settlements with all defendants.
  • Dilworth v. Chesapeake (McMullen County District Court, Texas 343rdJudicial District) – Sued Chesapeake for underpaying royalties on minerals produced in the Eagle Ford Shale. Secured favorable settlement for the Dilworth family.
  • Bell Textron Inc. v. Scott Drennan and Hyundai Motor America (Tarrant County District Court, Texas 96thJudicial District) – Part of a team that obtained a swift settlement on behalf of Drennan, Hyundai, and all potential defendants in connection with allegations of theft of trade secrets and violations of a non-compete agreement.
  • Griffith v. Waters (Dallas County District Court, Texas 134thJudicial District) – After parachuting in as trial counsel on the day of trial, obtained verdict for client through post-judgment briefing and oral argument in a real estate dispute valued over US$1M.

  • The Best Lawyers in America®—Recognized for Commercial Litigation (2024–2025)
  • Best Lawyers: Ones to Watch®in America—Recognized for Commercial Litigation (2021–2023)
  • Texas Lawyer’s Texas Legal Awards—“On the Rise” (2024)
  • Lawdragon—“500 Leading Energy Lawyers” (2023–2025)
  • D Magazine—“Best Lawyers Under 40” (2020)
  • Texas Super Lawyers—Recognized as a “Rising Star” (2020)

  • Board, Access to Justice Lab at Harvard Law School

Capabilities

Litigation/Trials
Commercial Litigation & Disputes
Antitrust/Competition
Intellectual Property
Patent Litigation
Copyright-Infringement Litigation
Trade Secrets, Non Competes & Restrictive Covenants
Trademark Litigation, Prosecution & Brand Protection
Advertising Litigation
Appellate & Critical Motions
Class Actions & Group Litigation
International Arbitration
Product Liability & Mass Torts
Securities, M&A & Corporate Governance Litigation
Financial Services
Technology, Media & Telecommunications
Oil & Gas

Key Matters

Some of the experience represented below may have been handled at a previous firm.

LeElle’s representative experience includes:

  • Kosmos Energy Sao Tome and Principe v. ERHC Energy (BVI) Limited (International Chamber of Commerce (London); Harris County District Court, Texas 157thJudicial District) – Represented Kosmos in a dispute over rights to conduct oil and gas exploration in the Exclusive Economic Zone off the coast of São Tomé and Príncipe. Oversaw dual-track litigation in the ICC and Harris County. Secured preliminary injunctions in both jurisdictions, summary judgment on liability in Harris County, and a complete victory at the ICC, including attorneys’ fees.
  • Torreya Partners LLC v. [Confidential] (American Arbitration Association) – Represented a pharmaceutical marketing firm in a dispute with a pharmaceutical manufacturing company over fees owed under a marketing agreement. After taking over for prior counsel within six months of arbitration, finalized a settlement two days before trial that far exceeded the client’s desired result.
  • Pizza Hut Inc. v. Accenture LLP (S.D.N.Y.) – Represented Pizza Hut in a breach of contract action against Accenture for failure to provide a software product. Filed suit immediately after pre-suit mediations ended at an impasse. The very next day, Accenture acceded to settlement demands and the parties executed a final agreement within four months. Obtained a settlement of the entire dispute with nothing more than filing a complaint.
  • DDR Holdings, LLC v. Hotels.com, L.P., et al. (E.D.T.X.) – Represented inventors and patent holders in a patent infringement suit against seven defendants involving third-party website design features. After a jury trial, won verdicts of infringement against the only two defendants who had not settled. Successfully defended the verdict on appeal to the Federal Circuit on a § 101 challenge—the first case to do so after the Supreme Court issued Alice Corp. v. CLS Bank Int’l.
  • Stonebriar Commercial Finance v. Zetta Jet et al. (Collin County District Court, Texas 380thJudicial District) – Won complete judgements (including award of attorneys’ fees) against defendants and then pursued enforcement actions in five different states including managing several related actions in Colorado state court and bankruptcy court. Negotiated the exchange of a private aircraft as part of the settlement agreement.
  • Stonebriar Commercial Finance v. Griffin Barges (S.D.T.X. and E.D.L.A.) – Seized four multimillion-dollar cargo barges (two in the Houston Ship Channel, two docked in New Orleans) used as collateral to secure a loan. Facilitated the subsequent sale of the barges, the proceeds of which fully covered the entire outstanding debt, and all attorneys’ fees.
  • Black Stone Minerals v. Chesapeake, PXP Louisiana, et al. (DeSoto Parish, Louisiana 42ndJudicial District) – Sued Chesapeake and PXP Louisiana (now Freeport-McMoRan) for underpaying royalties on minerals produced in the Haynesville Shale. Reached a favorable settlement with PXP within months of filing suit and with Chesapeake days before trial.
  • Black Stone Minerals v. Chesapeake, Total E&P, et al. (part of MDL in Tarrant County District Court, Texas 348thJudicial District) – Sued Chesapeake and Total for underpaying royalties on minerals produced in the Barnett Shale as part of the leadership in multidistrict litigation in Texas involving similar claims made by other royalty owners. Briefed, argued, and defeated multiple case-specific and MDL-wide summary judgment motions which resulted in settlements with all defendants.
  • Dilworth v. Chesapeake (McMullen County District Court, Texas 343rdJudicial District) – Sued Chesapeake for underpaying royalties on minerals produced in the Eagle Ford Shale. Secured favorable settlement for the Dilworth family.
  • Bell Textron Inc. v. Scott Drennan and Hyundai Motor America (Tarrant County District Court, Texas 96thJudicial District) – Part of a team that obtained a swift settlement on behalf of Drennan, Hyundai, and all potential defendants in connection with allegations of theft of trade secrets and violations of a non-compete agreement.
  • Griffith v. Waters (Dallas County District Court, Texas 134thJudicial District) – After parachuting in as trial counsel on the day of trial, obtained verdict for client through post-judgment briefing and oral argument in a real estate dispute valued over US$1M.

Credentials

Education

LeElle received her J.D., cum laude, from Harvard Law School in 2010, where she was editor-in-chief of the Harvard Journal of Law & Public Policy. She received her B.A., magna cum laude, in developmental neuropsychology and political science from Duke University in 2007.

    Admissions
    • Texas
    • New York
    Clerkships
    • USCA - Fifth Circuit for the Honorable Jerry E. Smith
    • USCA - Fifth Circuit for the Honorable Jerry E. Smith

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    Capabilities

    Litigation/Trials
    Commercial Litigation & Disputes
    Antitrust/Competition
    Intellectual Property
    Patent Litigation
    Copyright-Infringement Litigation
    Trade Secrets, Non Competes & Restrictive Covenants
    Trademark Litigation, Prosecution & Brand Protection
    Advertising Litigation
    Appellate & Critical Motions
    Class Actions & Group Litigation
    International Arbitration
    Product Liability & Mass Torts
    Securities, M&A & Corporate Governance Litigation
    Financial Services
    Technology, Media & Telecommunications
    Oil & Gas
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