People / Leslie Thorne
Thorne Leslie

Leslie C. Thorne

Partner | Chair - Litigation Department | Board Member New York Austin

Biography

When it comes to complex commercial litigation, a lawyer needs to understand her clients’ big picture business goals and objectives. Approaching disputes from this business-oriented perspective, Chambers-ranked Leslie C. Thorne has successfully represented the nation’s largest and most prominent corporations in jurisdictions throughout the United States. As Chair of the firm's Litigation Department, Leslie not only develops and executes effective strategies, she also makes sure that her clients are part of the process at every step. The better informed her clients are, the better able they are to make critical decisions affecting their businesses.

Leslie is widely recognized as a leader in her field and is currently ranked in Benchmark Litigation, Best Lawyers, and Chambers USA, where clients describe her as "exceptionally talented" and say "she has the ability to cut through a problem to the very core of it." Leslie co-founded and leads the firm’s Electric Power Litigation practice group, recognized as one of the nation’s 15 best by Legal 500, where clients say she is a "superb lawyer" and a "phenomenal strategist." Leslie has also been recognized by Legal 500 as a key partner in the firm’s top-ranked Insurance Recovery Group. She is also a Leading Litigator in New York according to Lawdragon 500. Leslie and her work have also appeared in—among others—Fortune, Bloomberg, New York Law Journal, Insurance Journal, Law360, Texas Lawyer, Houston Chronicle, Austin Business Journal, Intellectual Property & Technology Law Journal, Corporate Counsel Review, Executive Counsel Magazine, and many ABA publications. She speaks frequently at national conferences and seminars on all manner of insurance, energy and other litigation-related topics.

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  • (Texas Supreme Court) Currently represent power generators in billion-dollar fraud and misrepresentation suit against ERCOT, alleging that ERCOT misled generators and investors to incent investment.
  • (S.D.N.Y.) Currently represent executives of Fortune 10 company in SEC enforcement action.
  • (S.D. Tex. and Harris County) Currently represent multiple ERCOT market participants in mass tort claim related to Storm Uri.
  • (S.D.N.Y.) Currently represent national car rental company in $23 million coverage case stemming from SEC proceeding.
  • (N.Y. Sup. Ct.) Represented bank in $50 million dispute with trade credit insurer over coverage for accounts receivable for Mexican company.
  • (5th Cir) Represent wind generator in $350 million-dollar dispute concerning rights under Power Purchase Agreement.
  • (D.N.D.) Represent Fortune 10 company in $51 million liability coverage dispute over claims stemming from catastrophic well incident.
  • (W.D.Tex.) Represented Usenet/newsgroup service provider in multi-million dispute over trademark infringement claims.
  • (N.Y. Sup. Ct.) Represented chemical plant in $8 million dispute with general and pollution liability carrier over business interruption losses.
  • (N.D. Tex) Represented grid operator SPP in right-of-first-refusal dispute.
  • (Tex. App.—Austin) Represented REP/QSE in dispute with ERCOT over discriminatory treatment under ERCOT Protocols.
  • (N.Y. Sup. Ct.) Represented promotional marketing company in dispute with international advertising agency over multi-million-dollar joint venture dispute.
  • (Arbitration) Represent multi-national design and construction venture in $230 warranty claim brought by counterparty.
  • (D.N.D.) Represented oil and gas company in multi-million-dollar dispute over coverage for personal injury claims.
  • Obtained recoveries for real estate developers in construction defect cases involving multi-million dollar office buildings and hotels.
  • Secured a settlement with carriers in connection with MTBE-related claims made against Fortune 50 client.
  • Convinced the carrier to post supersedeas bond and provide appellate defense for energy company found liable for intentional private nuisance in connection with its oil and gas operations.
  • Secured dismissal of fiduciary duty and minority oppression claims against major shareholders in a healthcare corporation.
  • Successfully defended a bank at trial against a breach of contract claim.
  • Secured a settlement for a national energy company in connection with a failed ethanol venture.
  • Conducted an internal investigation and remediation of a data security breach at a national hotel chain.
  • Convinced insurers to cover extensive property losses caused by various hurricanes and other natural disasters.
  • Obtained a total victory for a corporate defendant at trial over an employment contract.
  • Advised national lenders of insurance needs for real estate development projects.
  • In an oil and gas dispute, secured a temporary restraining order and temporary injunction against a foreign sovereign pending international arbitration of dispute.
  • Obtained a favorable settlement for a corporate plaintiff in a fraud case involving theft of business.
  • Obtained a temporary restraining order preventing a landlord from terminating a commercial lease.
  • Obtained a total reversal of a tax assessment on aircraft.
  • Advised corporate policyholders regarding risk transfer strategies.
  • Helped corporate policyholders recover insurance monies from resistant carriers.
  • Represented owners and developers in construction disputes with architects, contractors and subcontractors.
  • Honorary Vice Chair, New York County Lawyers Association 2024 Annual Gala
  • Board member, Austin Bergstrom Landhost Enterprises
  • Board member, Texas Appleseed
  • The University of Texas Law School 2016 Essential Cybersecurity Law Conference, Presiding Officer
  • American Bar Association (Litigation Section)
  • American Bar Foundation Fellow
  • ABA Insurance Coverage Litigation Additional Insureds Subcommittee, Co-Chair
  • Robert W. Calvert American Inn of Court
  • Recognized in Chambers USA, Chambers and Partners, Band 2, for General Commercial Litigation in Texas, Austin & Surrounds, 2021-2023; Band 1 for General Commercial Litigation in Texas, 2024
  • Included in the Lawdragon 500 Leading Litigators in America guide, 2023-2025
  • Recognized by Benchmark Litigation, Euromoney Institutional Investor PLC, as an "Insurance Litigation Star", 2025
  • Recognized in Austin’s Top Attorneys, Austin Monthly, Open Sky Media, 2021-2022
  • Recognized by The Legal 500 U.S., Legalese, 2022-2024
  • Named 2019 Attorney of the Year by Texas Lawyer as part of their Professional Excellence Awards
  • Named “Local Litigation Star” in General Commercial and Insurance by Benchmark Litigation U.S., Euromoney Institutional Investor, PLC, 2019-2022
  • The Best Lawyers in America, Woodward/White, Inc., Insurance Law, 2018-2025; Litigation- Construction, 2023-2025; Litigation- Insurance, 2023-2024; Commercial Litigation 2023-2025
  • "Judge boots Jeffrey Simpson from his own firm," featured, The Real Deal, December 4, 2023. 
  • "New Suit Alleges Tech Company Diverted Development Loan to Pay Own Executives," featured, New York Law Journal, November 28, 2023.
  •  “Mitigating Exposure To PFAS Liability," co-author, Mealey’s Pollution Liability Report, September 20, 2022.
  • "Texas Grid Operator in Bankruptcy Showdown Over $2 Billion Charge," quoted, Bloomberg Law, February 10, 2022.
  • "A Look Back at Insurance Legislation and Regulation of 2021," author, Law360, December 21, 2021.
  • “Gas and Electric Power Lending, Swaps and Hedges: How To Handle the Force Majeure Fallout From the ERCOT Market Disaster,” author, New York Law Journal, April 2, 2021.
  • “Navigating Business Insurance Coverage in the Aftermath of Texas Power Crisis and Winter Storm,” author, Texas Lawyer, March 19, 2021.
  • “Who Will Pay for the Freeze and Subsequent Meltdown in Texas?,” author, Insurance Journal, March 16, 2021.
  • "Renewable Energy Cos. Need New Risk Management Tools," co-author, Law360, March 3, 2021.
  • “Liability Issues for Non-Profits,” presenter, 38th Annual Nonprofit Organizations Institute, January 22, 2021.
  • “Texas Environmental Law,” co-author, Volumes 45-46, Chapter 34 Insurance, Thomson Reuters, 2020-2021.
  • “Cyber Insurance in Context of Incident Response Plan,” presenter, The University of Texas School of Law 2020 Essential Cybersecurity Law Conference, July, 15, 2020.
  • “Insurance Coverage for Businesses’ COVID-19-Related Losses,” co-presenter, Austin Bar Association Remote CLE, April 15, 2020.
  • “COVID-19 Financial Risk Mitigation Tools,” presenter, UT Law CLE Studio Webcast, March 24, 2019.
  • “Texas Environmental Law,” co-author, Volumes 45-46, Chapter 34 Insurance, Thomson Reuters, 2019-2020.
  • "Crisis Management: Responding to a Data Breach," presenter, Center for American and International Law, September 12, 2019.
  • "Cybersecurity Insurance," presenter, The University of Texas School of Law 2017 Essential Cybersecurity Law Conference, July, 25, 2019.
  • “Update on Opioid Litigation,” presenter, Barclays High Yield Bond & Syndicated Loan Conference, Colorado Springs, CO, June 6, 2019.
  • "Expectations of Privacy in a Digital Age," co-presenter, Robert W. Calvert Inn of Court, Austin, Texas, November 13, 2018.
  • "The #MeToo Movement and Its Impact on Employment Claims & Coverage," presenter, ABA Women in Insurance Network, Dallas, Texas, November 8, 2018.
  • "Insurance Coverage for Cybersecurity Issues," presenter, Center for American and International Law 2nd Cybersecurity and Data Privacy Law Conference, April 12, 2018.
  • "2018 General Counsel Panel," panel moderator, Association of Corporate Counsel, Austin Chapter, April 12, 2018.
  • "What You Need to Know About Cybersecurity," presenter, Austin Bar Association Real Estate Section, April 10, 2018.
  • "Cybersecurity Planning: When (not if) a data breach occurs, will you be ready to respond?" speaker, University of Texas, School of Law Conference, Austin, Texas, February 23, 2018.
  • “Texas Environmental Law,” co-author, Volumes 45-46, Thomson Reuters, 2017 and 2018.
  • Data Security, Client Confidences, and Ethics Rules Applicable to the Protection of Client Information,” speaker, Texas Bar CLE 35thAnnual Advanced Tax Law Course, August 18, 2017.
  • “The In-House Perspective on Managing Cybersecurity,” panel moderator, The University of Texas School of Law 2017 Essential Cybersecurity Law Conference, July 28, 2017.
  • “What Every IP Lawyer Should Know about Insurance,” speaker, The University of Texas School of Law 2017 Technology Law Conference, May 25, 2017.
  • “2017 General Counsel Panel,” panel moderator, Association of Corporate Counsel, Austin Chapter, April 13, 2017.
  • "Ethical Considerations in Preparing Expert Witnesses to Testify at Deposition and Trial in an Insurance Coverage Case," speaker, ABA 25th Annual Insurance Coverage Litigation Committee Mid-Year Program, Phoenix, AZ, February 24, 2017.
  • “Data Security, Client Confidences, and Ethics Rules Applicable to the Protection of Client Information,” speaker, University of Texas School of Law 64th Annual Taxation Conference, December 1, 2016.
  • “Cybersecurity Insurance Policies,” speaker, The University of Texas Law School 2016 Essential Cybersecurity Law Conference, August 19, 2016.
  • "Cyber Liability: Surviving the Wild Frontier," speaker, Texas Insurance Academy, May 5, 2016.
  • "'Hired Gun' or 'Shooting Blanks'? The Balance Between the Two and Other Ethical Considerations in Preparing Expert Witnesses to Testify at Deposition and at Trial," speaker, ABA Insurance Coverage Litigation Committee Annual Seminar, Tucson, AZ, March 3, 2016.
  • "Jury Selection in Insurance Coverage Cases: The First Step to Winning at Trial," speaker, ABA Women of the Section of Litigation: Leading, Litigating & Connecting, Chicago, IL, November 12, 2015.
  • Testimony regarding HB 3646 before the Texas House Insurance Committee, April 22, 2015.
  • "Computer Fraud & Cybercrime: Isn't Technology Wonderful?" speaker, Robert W. Calvert Inn of Court, April 14, 2015.
  • 2015 General Counsel Forum, moderator, Association of Corporate Counsel, March 26, 2015.
  • "The Ethics of Witness Preparation in a Coverage Case:  Prepare Your Witness…But Not TOO Much!," speaker, ABA Insurance Coverage Litigation Committee Annual Seminar, Tucson, AZ, March 7, 2015.
  • "Claims Happen:  How to Manage Your Insurance When Hit with Litigation and Investigations," speaker, San Antonio Compliance Roundtable, February 25, 2015.
  • "Claims Happen:  How to Manage Your Insurance When Hit with Litigation and Investigations," speaker, Austin Compliance Roundtable, February 25, 2015.
  • "Practical Tips on Preventing, Managing, and Insuring for Data Breaches,” speaker, Houston Cybersecurity panel, February 18, 2015.
  • "Despite Bipartisan Support, Data Breach Law Faces Obstacles," author, Law360, February 02, 2015.
  • "Indemnification Agreements for the Energy World: Anti-Indemnity Statutes & Their Effects on Risk Transfer," speaker, Houston Bar Association, October 30, 2014.
  • "A Compliance Officer’s Guide to Cyberliability and Cyber Insurance," speaker, Houston Compliance Roundtable, October 15, 2014.
  • "What You Need to Know About Cybersecurity," speaker, presented to the Better Business Bureau of Central, Coastal, Southwest Texas and the Permian Basin, September 16, 2014.
  • "What You Need to Know About Data Security and Cyber Insurance: Practical tips on preparing for and responding to a cyber security breach," speaker, presented to public and private company clients in the Dallas area, June 26, 2014.
  • "Understanding Privacy, Cybersecurity, and Cyber Insurance," speaker, Austin Compliance Roundtable, May 28, 2014.
  • "What Registered Entities Need to Know about Cybersecurity and Cyber Insurance," speaker, San Antonio Compliance Roundtable, May 14, 2014.
  • "Negotiating AIA Construction Contracts: The Owner’s Perspective," speaker, Lorman AIA Contracts Seminar, May 7, 2014.
  • "Cyber Liability and Loss Seminar," speaker, presented to public and private company clients in the Austin area, April 22, 2014.
  • "Insurance Coverage for a Young and Growing Business: What You Need to Know," speaker, TexasBarCLE Essentials of Business Law Course, March 7, 2014.
  • "Insurance Coverage for Cyber Attacks: What Do You Need in a Cyber Liability Policy?" co-author, Haynes and Boone Client Alert, February 27, 2014.
  • "Water Rights of Fracking Operations," speaker, Robert W. Calvert American Inn of Court presentation, February 10, 2014.
  • "Texas Supreme Court Reaffirms All Sums Allocation Approach for Continuous Losses," speaker, ABA Section of Litigation, Insurance Coverage Notes, October 30, 2013.
  • "The Corporate Representative Deposition: Uses & Abuses," speaker, TexasBarCLE 26th Annual Advanced Evidence & Discovery Course, May 24, 2013.
  • "Fisher v. Texas and the Future of Race-Conscious Admissions," speaker, Robert W. Calvert American Inn of Court presentation, April 9, 2013.
  • "Q&A With Haynes and Boone's Leslie Thorne," author, Law 360, March 27, 2013.
  • "Top Construction Contract Issues and Pressure Points for the Players," speaker, University of Texas School of Law 2012 Construction Law Program, September 13, 2012.
  • "Construction Anti-Indemnification Law Changes Indemnity and Additional Insurance Landscape," speaker, ABA Section of Litigation, Insurance Coverage webpage of the Insurance Coverage Committee, May 2012.
  • "CGL Policies Triggered by Allegations of Physical Damage to Adjacent Property," speaker, ABA Section of Litigation, Insurance Coverage News & Developments, May 4, 2012.
  • "Disastrous 2011 a Reminder to Obtain Sufficient Coverage," guest column, PropertyCasualty360, November 3, 2011.
  • "How Can Insurance Agents Help the Texas Fire Victims?," guest column, Insurance Journal, Sept. 13, 2011.
  • "Insuring Against Risks with Sustainable Hotels," guest column, Lodging Hospitality, Aug. 18, 2011.
  • "Insurance Considerations for Construction Projects," speaker, Fundamentals of Construction Contracts: Understanding the Issues, Lorman Education Seminars, July 27, 2011.
  • "New Texas Construction Anti-Indemnification Law - HB 2093," author, Haynes and Boone Client Alert, June 27, 2011.
  • "Insurance Coverage for Storm Devastation," author, Law360 Guest Column, June 1, 2011.
  • "Annual Review of Litigation, Chapter 3: Appellate Practice," contributor, with Kendyl Hanks and Mark Trachtenberg, American Bar Association, Section of Business Law, April 2011.
  • "Securities Litigation and The Supreme Court: 2010 in Review and a Preview of 2011," co-author with Nicholas Even and Daniel Gold, University of Texas School of Law 33rd Annual Conference on Securities Regulation and Business Law, February 2011.
  • "Insurers, sureties slow to respond to green builders' needs," guest column, Austin Business Journal, June 25, 2010.
  • "Changes in the 'Actual Prejudice' Requirement: Effects of Late Notice and Settlement Without Consent When the Insurer Cannot Show That It Has Been Harmed," speaker, University of Houston Law Foundation Advanced Insurance and Tort Claims Program, 2008.
  • "CCIPS, OCIPS, and Other Risk Transfer Strategies: Considerations for Construction Projects," speaker, 2008.
  • "Insurance and Other Risk Transfer Strategies: Considerations for Construction Projects," speakers, Fundamentals of Construction Contracts: Understanding the Issues, Lorman Education Seminars, 2008.
  • "Frank's Casing and Its Impact on Stowers," speaker, State Bar of Texas Telephone CLE Seminar Series, 2008.
  • "How to be a Successful Summer Associate," speaker, University of Oklahoma School of Law, 2008.
  • "Additional Insured Coverage: Emerging Issues," speaker, 2007.
  • "Selection of Counsel and Ethical Dilemmas in the Tripartite Relationship," speaker, 2007.
  • "Recovering Business Losses: Hurricane and Other Business Interruptions," speaker, University of Houston CLE, Advanced Insurance and Tort Claims, March 22, 2007.
  • "Insurance Policy: Perils and Gaps," author, Executive Counsel Magazine, March/April 2006.
  • "What Every Business Needs to Know About Insurance," author, Corporate Counsel Review, Volume XXV Number 2, November 2006.
  • "Offers of Settlement, Texas Rules of Civil Procedure 167: A Plaintiff Attorney Perspective" speaker, 2004.
  • "Spoliation & Retention in the Computer Age" speaker, 2004.

Education

J.D., The University of Texas School of Law, 2004

B.A., The University of Texas at Austin, 2001

Admissions

New York

Texas

North Dakota

New Jersey

Court Admissions

U.S. Court of Appeals for the Second Circuit

U.S. Court of Appeals for the Fifth Circuit

U.S. Court of Appeals for the Eighth Circuit

U.S. District Court for the Eastern District of New York

U.S. District Court for the Southern District of New York

U.S. District Court for the District of North Dakota

U.S. District Court for the Northern District of Texas

U.S. District Court for the Southern District of Texas

U.S. District Court for the Western District of Texas

U.S. District Court for the Eastern District of Texas

United States Supreme Court

U.S. District Court for the District of New Jersey

Practices and Industries
AttorneyS of the Year

Leslie Thorne and Emily Westridge Black honored as Attorneys of the Year (2019) by Texas Lawyer for their successful work on behalf of a Honduran woman seeking asylum.

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News/Insights Explore all news and insights
Courtroom2
Press Release

Benchmark Litigation Recognizes 8 Haynes Boone Attorneys and 2 Practices in 2025 Rankings

October 04, 2024
Courtroom3
Press Release

8 Haynes Boone Lawyers Recognized as 2025 Lawdragon 500 Leading Litigators in America

September 10, 2024
new york city
Publication

Guinn and Thorne in New York Law Journal: Amendments to EDNY and SDNY Local Rules and Their Impact on Litigation

August 28, 2024