• Lead counsel for a private equity investment advisor and one of its portfolio companies in a lawsuit against the portfolio company’s former executive team and a competitive private equity investment advisor, based on corporate usurpation, conspiracy, breach of fiduciary duty and misappropriation of trade secrets, in which Marc’s client was seeking in excess of $700 million. After nine weeks of trial, on the eve of closing arguments, the case ended with an extremely favorable settlement for Marc’s client.
• Represented a large private equity investment advisor with $20 billion of assets under management, along with its president and founder, in litigation involving fiduciary duty, as well as shareholder-derivative, defamation and contractual claims, in which the recovery being sought against Marc’s clients was $200 million. After an almost four-week trial, Marc obtained a take-nothing verdict in favor of his clients, along with a recovery of $2.8 million in attorneys’ fees for his clients.
• Successfully obtained dismissal of a patent-infringement action in which damages sought against Marc’s client were in excess of $500 million.
• Obtained a transfer of intellectual-property rights in favor of a major jewelry manufacturer whose patents and other intellectual property had been misappropriated by the former president and chief executive officer.
• Successfully reached a defense verdict on a commercial-fraud case in which damages sought against the client were in excess of $100 million.
• Achieved a total victory in favor of the former president of a national health insurance company in a noncompetition and trade-secret trial.
• Represented one of the nation’s largest independent specialty pharmacies in a lawsuit against a former software provider for misappropriation of trade secrets and unauthorized use and disclosure of confidential information. Relying heavily on forensic evidence and expert testimony, obtained favorable preliminary rulings for our client, allowing a successful resolution that included the opposition’s agreement to the permanent injunctive relief that was sought, as well as payment of attorneys’ fees.
• Represented a major global investment bank in litigation against a major creditor that defaulted on a loan and used the proceeds for fraudulent purposes. Through litigation and evidence obtained through cutting-edge forensic efforts, successfully recovered all misappropriated funds.
• Represented a major global energy firm in a series of disputes involving multiple C-level executives and board members involving bet-the-company level matters and ultimately obtaining favorable resolutions for the client.
• Obtained successful resolution in a contested ownership dispute for a major North Texas sports franchise.  
• Defended a leading national electrical equipment manufacturing company in an intellectual property dispute in federal court in Texas. After extensive discovery, briefing, and hearing, successfully defeated the plaintiff’s attempt to secure a preliminary injunction.  Given clear indications from the court that it would be granting summary judgement in the client’s favor, we settled the matter for less than 0.5% of the millions of dollars in damages initially sought by plaintiff.   
• Defended a company and its CEO in a lawsuit alleging fraud in which plaintiff was seeking recovery of more than $200 million and obtained a complete defense verdict following a week-long trial in Texas state court.   
• Successfully defended a multi-level marketing company in numerous lawsuits brought by competitors alleging violations related to non-competition matters and obligations. Obtained comprehensive resolutions after successfully arguing that the non-competition agreements at issue were unenforceable. 
• Lead counsel for private–equity backed group of surgical centers, defending claims of disability discrimination and retaliation by a former owner and prosecuting claims for forfeiture of transaction proceeds and equity against the same individual. The former owner was seeking in excess of $20 million, but after a one-week arbitration the former owner agreed to the dismissal of all of his claims, as well as to all of the relief sought by our client. 
• Represented the audit committee of a leading provider of AI–based business solutions in connection with an investigation into allegations of sexual harassment by a company executive.  
• Represented a multinational networking and telecommunications company in connection with an investigation into claims made by an outgoing company executive.   
• Led an investigation on behalf of a global communications service provider facing allegations that high-level executives were violating the company’s code of conduct and, while in the process of doing so, uncovered evidence that an employee had been compromised by a foreign government, allowing the company to take swift action to mitigate potential negative effects of the situation.  
• Represented the audit committee of an American amusement park company in connection with an investigation into allegations of discrimination, retaliation, and violations of the company’s conflicts of interest policy by C-level executives and other high-level members of company management. 
• Obtained a complete defense victory for a global internet and technology company in an arbitration dealing with allegations of sexual harassment and retaliation, with potential damages stretching into the hundreds of millions of dollars, and successfully upholding the award through federal court appeals up through the 9th Circuit. 
• Led an investigation into allegations that a former business owner misrepresented various corporate issues, including allegations of sexual harassment, during the due diligence conducted by our client prior to the purchase. 
• Represented a global IT and software development company in a whistleblower matter before the U.S. Department of Labor.  The matter was dismissed at the pleading stage for lack of jurisdiction. 

Bar Admissions

• Colorado
• New York
• Texas

Court Admissions

• U.S. District Court for the Northern District of Illinois
• U.S. District Court for the Southern District of Illinois
• 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 Eastern District of Texas

Education

• J.D., University of California, Berkeley, School of Law (1994)
• B.A., Emory University (1991)

Bylines

• Co-Author, “Employment Issues Facing Energy Companies in 2021 and Beyond,” POWER Magazine, January 4, 2021
• Co-Author, “COVID-19 Employment Law: New and Emerging Compliance Challenges,” Texas Lawyer, December 2020
• Co-Author, “Employment Law in the Year of COVID-19: A Review of New and Emerging Compliance Challenges Facing Employers in 2020 and Beyond,” Texas Lawyer, October 2020
• Staying on Top of New Management Liability Regulations and Their Impact on Employers Inside the Minds: Protecting Corporations Against Management Liability Claims — Leading Lawyers on Analyzing Developments in Employment Regulations, Investigating and Responding to Allegations, and Creating Effective Compliance Strategies, Aspatore Books, 2013
• Understanding Key Changes in Employment Law Regulations and Their Impact on Defense Strategies Inside the Minds: Strategies for Employment Litigation — Leading Lawyers on Successfully Litigating and Settling Employment Claims, Aspatore Books, 2012
• Instructor, DAYL Trial Skills Boot Camp, 2015-2017
• “Trade Secret Claims Under the Texas Uniform Trade Secrets Act,” September 17, 2015
• “Decision Dynamics in Non-Compete Cases,” UT CLE 2015 Non-Compete Camp: Drafting, Litigating and Trying Non-Competes, September 3, 2015
• “Pertinent Trends Affecting Energy Sector and Compliance Issues During Corporate Layoffs,” March 12, 2015

• “2026 Texas General Counsel Sports Forum,” Moderator, April 29, 2026
• “More DLA Piper Employment Attorneys Join Vartabedian Katz,” Law360, March 4, 2026
• “Vartabedian Katz Hester & Haynes Adds Three More Employment Lawyers from DLA Piper”, The Texas Lawbook, March 3, 2026
• “Six-Lawyer DLA Piper Employment Team Moving to Dallas Boutique, Led by Practice Chair Marc Katz”, Texas Lawyer, February 19, 2026
• “Katz Teams Up with Vartabedian,” The Texas Lawbook, February 17, 2026
• “Firm Rebrands To Vartabedian Katz With DLA Piper L&E Team,” Law360, February 17, 2026
• “Office Snapshot: A Look At DLA Piper’s Dallas Outpost,” Law360, April 13, 2021
• “Diversity Rising: COVID-19 Employment Law,” Texas Lawyer, December 2020
• “Attorneys React To DOL’s Final Overtime Exemption Rule,” Law360, May 18, 2016
• “For Lone Rangers Corporate Lawyer, Baseball is Appealing Environment,” The Dallas Morning News and The Texas Lawbook, April 4, 2016
• “What Does Hobby Lobby Mean for Texas Employers?” Texas Lawyer, Vol. 30, No. 15, p. 9, July 7, 2014
• “Prepare protocol for guestroom theft scenarios,” hotelmanagement.net, August 3, 2010
• Commentator, Personnel Legal Alert, Alexander Hamilton Institute, Inc., Vol. 21, No. 12, November 16, 2009

• Chambers USA
  • Band 3, Texas Labor & Employment, (2023-2025)
  • Band 4, Texas Labor & Employment, (2018-2022)
• The Legal 500 United States
  • Recommended, Workplace and Employment Counseling, (2023-2025)
  • Recommended, Labor-Management Relations, (2023-2025)
  • Recommended, Labor and Employment Disputes (Including Collective Actions): Defense, (2018-2025)

Other Recognitions

• Super Lawyers- Employment & Labor, Intellectual Property Litigation (2013 – 2026)
• The Best Lawyers in America for Litigation – Labor and Employment (2024)
• Best Lawyers in Dallas, D Magazine, (2011-2012, 2014-2021)
• Super Lawyers by Thomson Reuters, published in Texas Monthly (2015-2020)
• Top 100 Texas Lawyers and Top 100 Dallas/Fort Worth Lawyers (2015-2016)
• Mentor of the Year, Dallas Urban Debate League (2010-2011)
• Texas Rising Star, Super Lawyers by Thomson Reuters, published in Texas Monthly (2004-2009)
• Dallas Chamber of Commerce, Dallas Leadership Program (2006)
• Member, The City of Dallas Park and Recreation Board (2005-2006)
• Best Lawyers Under 40 in Dallas, D Magazine (2004)
• Board Certified – Labor and Employment Law, Texas Board of Legal Specialization
• Texas Association of Business & Chambers of Commerce, Associate Editor