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    Home /  Lawyers /  Diane L. McGimsey

    Diane L. McGimsey

    Partner

    Diane L. McGimsey Headshot Photo Portrait backdrop

    Los Angeles

    +1-310-712-6600

    |

    mcgimseyd@sullcrom.com

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    Diane McGimsey is a member of the Firm’s Litigation Group. Before joining S&C, she served as a law clerk to Justice Clarence Thomas of the U.S. Supreme Court and to Chief Judge J. Harvie Wilkinson III of the U.S. Court of Appeals for the Fourth Circuit.

    Ms. McGimsey has represented clients in a wide range of federal and state litigation matters at both the trial and appellate level, with a particular focus on shareholder litigation and the defense of private class action securities and antitrust litigation. Her practice also includes investigations by the Department of Justice and the Securities and Exchange Commission, as well as handling matters for clients as plaintiffs in significant commercial disputes.

    Community Service

    • Member of Board, Western Justice Center
    • Member of Board, Salvatori Center for the Study of Individual Freedom
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    Spotlight

    S&C Critical Insights – A Discussion of Recent Federal Arbitration Act Decisions

    Listen to podcastPlay Video

    Diane McGimsey and Adam Paris Selected as Los Angeles Business Journal’s “Leaders of Influence” 

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    S&C Prevails at Trial in Real Estate Loan Dispute

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    • Experience
    • Rankings and Recognitions
    • News
    • Publications, Videos and Podcasts
    • Credentials
    • Related Practices
    Experience

    Experience

    Securities and Complex Commercial Litigation

    • Volkswagen AG, in its landmark $14.7 billion settlement that solves civil claims related to 475,000 2.0-liter diesel engine vehicles in the United States. The resolution was achieved with multiple government agencies, 44 U.S. states and private plaintiffs. Also advised Volkswagen on its 3-liter class action and regulatory settlements.
    • Real estate investor Richard D. Cohen in obtaining a favorable ruling in a federal bench trial in the Southern District of New York over Mr. Cohen’s personal liability for a loan obtained by entities he controlled to buy a San Francisco residential apartment complex known as Rincon Center.
    • BP p.l.c. in securities class action litigation arising out of the August 2006 shutdown of the facilities in Prudhoe Bay, Alaska, including in a successful interlocutory appeal to the Ninth Circuit

    • JPMorgan Chase and its affiliates in connection with litigation related to residential mortgage backed securities
    • TCL Chinese Theatres, in litigation over permitted uses of the Dolby Theatre in Los Angeles, a live-performance auditorium used to host the Academy Awards
    • Standard Chartered Bank in investor arbitrations and litigations relating to investments to feeder funds to Bernard L. Madoff Securities
    • RBC Capital Markets and other underwriters in a class-action litigation relating to the U.S. Auto Parts Network, Inc. IPO
    • Thomas Weisel Partners in FINRA disciplinary proceeding alleging fraud in connection with the sale of auction rate securities
    • The former CEO of International Rectifier in class action and derivative litigation, SEC and criminal investigations relating to a restatement, and trade secret and wrongful termination litigation
    • UBS Securities in class action and derivative litigation relating to the sale of Hollywood Entertainment to Movie Gallery
    • General Growth Properties (“GGP”) in an appeal of an adverse $95 million judgment in an action by a rival mall developer on a claim of tortious interference (another firm represented GGP during the underlying trial)

    M&A-Related Litigation

    • CEO and Chairman of Activision-Blizzard in litigation over a transaction involving the restructuring of Vivendi’s ownership
    • Amylin in expedited litigation in Delaware Chancery Court, and later in an appeal to the Delaware Supreme Court, relating to a proxy contest
    • Hilton Hotels in litigation relating to its acquisition by Blackstone
    • Mitsubishi UFJ Financial Group in litigation relating to its acquisition of UnionBanCal Corporation
    • Swift Transportation in litigation relating to a going private transaction

    Antitrust Litigation

    • BP West Coast Products in a class action involving alleged manipulation of retail gas prices
    • Cablevision Systems Corporation in a class action challenging the bundling of cable programming
    • EnCana Corporation in multiple antitrust actions involving alleged manipulation of natural gas prices

    Governmental, Regulatory and Other Investigations

    • FinTech company in conducting an internal investigation and responding to high-profile allegations of a toxic environment due to sexual harassment and misconduct
    • Former CEO of Fortune 500 semiconductor company in DOJ and SEC investigations relating to alleged accounting irregularities
    • Thomas Weisel Partners in FINRA investigation and disciplinary proceedings relating to transactions involving auction rate securities
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    Rankings and Recognitions

    Rankings and Recognitions

    • AmLaw Litigation Daily – Runner Up, “Litigator of the Week” (January 2022)
    • Benchmark Litigation – Labor & Employment Star (2021, 2022, 2023)
    • Daily Journal – Top Women Lawyers (2016, 2017, 2018)
    • Law360 – Rising Star in Banking (2015)
    • Los Angeles Business Journal – recognized as one of the “Women Making a Difference” in Los Angeles (2014, 2015)
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    News

    News

    • S&C Obtains Complete Dismissal of Antitrust Class Actions Against BP

      January 25, 2023
    • S&C Prevails at Trial in Real Estate Loan Dispute

      January 19, 2022
    • MFA West 2018

      May 8, 2018
    • S&C Sponsors Women Corporate Directors’ BoardNext – Southern California Event on Internal Investigations

      February 7, 2018
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    Publications, Videos and Podcasts

    Publications, Videos and Podcasts

    • A Discussion of Recent Federal Arbitration Act Decisions

      Podcasts March 8, 2023
    • Supreme Court Business Review: Viking River Cruises v. Moriana and Southwest Airlines Co. v. Saxon

      Podcasts September 19, 2022
    • S&C Labor & Employment Lawyers Author Employers’ Guide to Return-to-Work Considerations

      Articles May 21, 2020
    • Critical Labor and Employment Insights

      Webinars April 7, 2020
    • Sexual Harassment Investigations in Light of the #MeToo Movement

      Podcasts April 16, 2019
    • Diane McGimsey and Judson Littleton Co-author Expert Q&A on Seeking and Opposing Certiorari in the U.S. Supreme Court for Practical Law

      Articles February 2018
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    Credentials

    Credentials

    Education

    • UC Berkeley School of Law, J.D., 2002
    • Claremont McKenna College, B.A., 1999

    Bar Admissions

    • California

    Clerkships

    • The Honorable Clarence Thomas, United States Supreme Court, 2003-2004
    • The Honorable J. Harvie Wilkinson III, United States Court of Appeals, Fourth Circuit, 2002-2003
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    Related Practices

    Related Practices

    • Litigation
    • Antitrust
    • Corporate Culture, Workplace Investigations & Whistleblower Litigation
    • Environmental, Social and Governance (ESG)
    • Financial Services Investigations & Litigation
    • Labor & Employment
    • Products Liability & Mass Torts
    • Supreme Court and Appellate
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