Mariquita Barbieri, chair of the firm’s Tax practice group, is a highly skilled tax and M&A attorney with a record of negotiating and closing complex, high-value transactions. With her background as a former corporate counsel, she now serves as outside general counsel, offering pragmatic legal and business guidance across industries.
A seasoned dealmaker, Mariquita customizes solutions to align with her clients’ goals, regardless of transaction size. She has more than 20 years of experience leading and executing high-value mergers, acquisitions, and divestitures across a range of industry sectors, including technology, health care, financial services, manufacturing, energy, retail, food and beverage, real estate and construction, transportation and logistics, and entertainment and media. She has successfully guided clients through complex transactions, delivering tailored solutions that align with each industry’s unique regulatory and operational landscape. Drawing on her experience in structuring deals, managing due diligence, and navigating compliance challenges, Mariquita helps businesses optimize their strategies and achieve growth in highly competitive markets.
With a Master of Laws in Taxation, Mariquita has a deep understanding of tax implications in corporate transactions. She specializes in private equity, hedge funds, and joint ventures, crafting innovative tax solutions for domestic and international challenges. Her experience in tax-deferred reorganizations for multimillion-dollar corporations allows her to develop strategies that maximize value and minimize risk.
With in-house counsel experience at a Fortune 500 bioproducts company, Mariquita offers a unique perspective on regulatory compliance, particularly with FDA, USDA, and EPA regulations. She has led initiatives to create best-practice templates, manage internal ethics investigations, and develop crisis management strategies that reduce corporate risk and exposure. While in-house, Mariquita also served as the U.S. data privacy lead, advising on the implementation of global privacy and data security programs, including GDPR compliance, she and continues to help clients navigate the complexities of data protection. Adept at aligning cross-functional teams and navigating regulatory landscapes, Mariquita facilitates seamless transitions and operational synergies throughout a company’s life cycle and after a strategic transaction.
As corporate counsel and assistant secretary at a division of DuPont Nutrition & Health, Mariquita served as general counsel for three major divisions, managing corporate matters, trade compliance, employment law, tax, and M&A. Her collaboration with business leaders protected intellectual property, secured trade secrets, and facilitated licensing and sales across North America, Europe, Asia-Pacific, and Latin America. With a track record in identifying and closing strategic deals, Mariquita has driven significant business growth, expanded capabilities, and delivered shareholder value.
experience
M&A and Tax Transactions
- Led strategic private equity and venture capital investments for family offices and investors across a range of industries, driving growth and innovation.
- Spearheaded the sale of a Midwest supplier specializing in cutting tools, coolants, and gauging products, enhancing market reach and operational efficiency.
- Facilitated the stock purchase and sale of a regional architectural firm, ensuring a seamless transition and positioning the firm for future growth.
- Directed the reorganization under IRC Sections 355 and 368 for a multi-disciplinary wealth management and benefits firm, optimizing its operational structure and tax efficiency.
- Oversaw the reorganization under IRC Sections 355 and 368 for a multinational investment portfolio firm, enhancing strategic alignment and investment capabilities.
- Managed the reorganization under IRC Sections 355 and 368 for a regional pool construction and sales business, streamlining operations to bolster competitive advantage.
- Navigated the Hart-Scott-Rodino filing for a $150 million to $200 million acquisition of a majority interest in a retail clothing brand, achieving a strategic foothold in the market.
- Led the asset purchase and sale of intellectual property and related assets for a non-shingle building integrated photovoltaic product, promoting innovation in sustainable building solutions.
- Oversaw the asset purchase and sale of a global inoculant and biological seed treatment business, expanding product offerings and enhancing agricultural sustainability.
- Played a pivotal role in the $6.3 billion acquisition of an international confection and ingredients producer, significantly enhancing market presence and product diversification.
Compliance and Ethics
- Developed and implemented comprehensive risk management controls and policies, including compliance training and risk assessments for antitrust, export controls, anti-boycott, FCPA, product stewardship, and code of conduct, ensuring organizational integrity and compliance.
- Spearheaded the creation of a contract database to effectively manage the company’s obligations, enhancing efficiency and accountability.
- Managed and executed policies to ensure compliance with FDA, EPA, and USDA regulations, safeguarding the company’s operations within the regulatory landscape.
- Conducted internal ethics investigations and led crisis management teams, successfully minimizing risks and penalties while maintaining corporate reputation.
- Guided the restructuring of the North American distribution network, establishing a model for future EU restructuring initiatives that improved operational efficiency.
- Designed and enhanced best-practice templates for confidentiality agreements and commercial transactions, streamlining processes and ensuring legal robustness.
- Led an FCPA investigation and drafted strategic recommendations in response to an SEC inquiry, reinforcing compliance and transparency.
- Determined reporting requirements for customs and rules of origin, providing essential guidance for the regulatory team to navigate complex compliance issues.
- Identified and verified sources of ingredient supply, implementing improvements to the manufacturing chain that optimized production efficiency.
- Successfully resolved rules of origin and customs inquiries with non-U.S. customers, facilitating smoother international transactions and maintaining strong customer relationships.
- Successfully guided clients through data breach incidents and privacy inquiries, ensuring compliance with regulations and minimizing risks while protecting sensitive information.
Professional
- American Bar Association, Tax Section
- The Illinois Bar
- The Missouri Bar
- Bar Association of Metropolitan St. Louis
- International Association of Privacy Professionals, Certified Information Privacy Professional (CIPP)
Community
- Association of Corporate Growth, St. Louis Chapter, Membership Committee, 2016-Present
- Central Institute for the Deaf, Board of Directors, 2009-Present
- Listed in The Best Lawyers in America (by BL Rankings) for Corporate Law, 2024, 2025
- Missouri & Kansas Super Lawyers (by Thomson Reuters), Mergers & Acquisitions, 2021
- 40 Under 40, St. Louis Business Journal, 2018
- Top 100 People to Know to Succeed in Business, Small Business Monthly, 2017
- Top Small Business Lawyer, Small Business Monthly, 2016
- Leadership Award, Dupont Nutrition and Health, 2009
I enjoy traveling with my husband and family, and I have a strong appreciation for Southwest art, which often inspires my creativity. I’m a fan of college basketball, enjoying the excitement of the game and the connections it fosters. I also have an interest in interior design and enjoy incorporating that into our home.