Grant Thornton Belgium completes deal, joins Grant Thornton Advisors multinational platform
CHICAGO and BRUSSELS, November 14, 2025 – Grant Thornton Belgium has completed a transaction that makes it part of the Grant Thornton Advisors multinational platform — which was established in January 2025 with the support of an investor group led by New Mountain Capital.
This agreement further enhances the wealth of capabilities and seamless connections of the Grant Thorton Advisors’ unique platform, building on the recently announced platform transactions with Grant Thornton member firms across Europe — in Ireland, France, Spain, Luxembourg, the Netherlands, Switzerland/ Liechtenstein, Poland and the Channel Islands.
Beyond Europe, the platform includes Grant Thornton firms in the UAE and the Cayman Islands and has recently announced transactions with the New Zealand and Brazil firms. The platform also includes Auxis, a pioneer in outsourcing and business modernization services, and Stax, which specializes in commercial due diligence and value creation.
Grant Thornton Belgium is a respected market leader rooted in globally strategic locations playing an integral role in the European Union. Its more than 250 professionals are deeply experienced in services related to cross-border mandates and mergers and acquisitions, as well as a range of audit, accounting, tax, legal and advisory needs.
Through this transaction, the Grant Thornton Advisors platform will accelerate its growth in the region. Clients will benefit from access to an even more extensive array of industry expertise and innovative solutions, amplified by substantial investments in technology and talent.
It remains part of the Grant Thornton International Limited network, which comprises member firms in more than 150 markets worldwide.
The transaction was originally announced in September of 2025.
About Grant Thornton
Grant Thornton delivers professional services in the US through two specialized entities: Grant Thornton LLP, a licensed, certified public accounting (CPA) firm that provides audit and assurance services ― and Grant Thornton Advisors LLC (not a licensed CPA firm), which exclusively provides non-attest offerings, including tax and advisory services.
In January 2025, Grant Thornton Advisors LLC formed a multinational, multidisciplinary platform. The platform offers a premier advisory and tax practice, as well as independent audit practices. With offices across the Americas, Europe and the Middle East, the platform delivers a singular client experience that includes enhanced solutions and capabilities, backed by powerful technologies and a roster of almost 20,000 quality-driven professionals enjoying exceptional career-growth opportunities and a distinctive cross-border culture.
Grant Thornton is part of the Grant Thornton International Limited network, which provides access to its member firms in more than 150 global markets.
Grant Thornton LLP, Grant Thornton Advisors LLC and their respective subsidiaries operate as an alternative practice structure (APS). The APS conforms with applicable laws, regulations and professional standards, including those from the American Institute of Certified Public Accountants.
“Grant Thornton” refers to the brand under which the member firms in the Grant Thornton International Ltd (GTIL) network provide services to their clients and/or refers to one or more member firms. Grant Thornton LLP and Grant Thornton Advisors LLC serve as the U.S. member firms of the GTIL network. GTIL and its member firms are not a worldwide partnership and all member firms are separate legal entities. Member firms deliver all services; GTIL does not provide services to clients.
About Grant Thornton Belgium
Grant Thornton Belgium is a full-service business advisor with strong expertise in audit, accountancy, tax and legal, and advisory. With over 250 employees across 7 locations in Belgium, we offer a full range of services to help clients of all sizes address the challenges and opportunities for growth.
Our local teams and member firms worldwide work and train together, sharing industry expertise and technical expertise, and a commitment to excellence.
For more information on Grant Thornton Belgium, please visit https://www.grantthornton.be/en/.
About New Mountain Capital
New Mountain Capital is a New York-based investment firm that emphasizes business building and growth, rather than debt, as it pursues long-term capital appreciation. The firm currently manages private equity, credit and net lease investment strategies with approximately $55 billion in assets under management. New Mountain Capital seeks out what it believes to be the highest quality growth leaders in carefully selected industry sectors and then works intensively with management to build the value of these companies. For more information on New Mountain Capital, please visit newmountaincapital.com.
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![Stephen Tennant]()
Stephen Tennant Stephen is the managing partner of Grant Thornton Ireland and previously led the firm’s financial services advisory practice. He has extensive experience in delivering practical solutions to regulatory challenges faced by global financial institutions.View Profile
