Grant Thornton Ireland and Grant Thornton US unite

Grant Thornton Advisors LLC in the US and Grant Thornton Ireland to Combine

• Brings together two closely aligned members of the Grant Thornton international network — tapping into complementary portfolios and a shared commitment to best-in-class quality and client service.
• Global expansion accelerates growth trajectory across the US, Ireland, Bermuda, Isle of Man and Gibraltar.
• Creates a cross-continental professional services platform with access to international top talent and deep expertise to solve clients’ most complex business challenges.

Grant Thornton Advisors LLC (Grant Thornton Advisors) and Grant Thornton Ireland, today announced an agreement to combine Grant Thornton Advisors with Grant Thornton Ireland’s advisory and tax businesses, with backing from an investor group led by New Mountain Capital, a leading growth-oriented investment firm with approximately $55 billion in assets under management. 

The Grant Thornton Ireland audit business will continue as an independent partnership and operate under an alternative practice structure.

Grant Thornton Advisors is a US-based tax and advisory services provider operating in an alternative practice structure alongside Grant Thornton LLP, a licensed certified public accounting firm that provides audit and assurance services. Together, the two providers go to market as the Grant Thornton brand in the US — most recently achieving record annual revenue of $2.4 billion and operating more than 40 US offices that employ almost 10,000 professionals.

Grant Thornton Ireland is a leading audit, tax and advisory services provider in Ireland, most recently achieving record annual revenue in excess of €300 million ($333 million). 

“This is a landmark year, as we’re commemorating Grant Thornton’s 100th anniversary in the US, and I can’t think of a better way to do it than by spearheading a seamless and integrated global platform with Grant Thornton Ireland — one that puts us in the vanguard of high-growth and high-quality firms,” said Seth Siegel, CEO of Grant Thornton Advisors.

“We share a common focus on client centricity, culture and delivering the highest quality results on a global scale. This strategic move signals a pivotal time in our industry that enables our clients to benefit even more from our innovative services with industry-leading execution, and bolsters accelerated and meaningful career-growth opportunities for all our professionals.”  

Steve Tennant, CEO of Grant Thornton Ireland added: “This transformational partnership will enhance our appeal to a much broader international client base, as the first truly integrated US and Irish professional services firm, combining the expertise and reach of both firms. This is a key moment in shaping the future of professional services in a rapidly evolving global landscape, and we are looking forward to partnering together to accelerate growth and deliver impactful benefits for our people and clients across diverse industries and geographies.” 

“New Mountain Capital is proud to support the coming together of Grant Thornton in the US and Ireland. This is an exciting step forward in our growth strategy that enhances the Grant Thornton brand and international capabilities,” said Andre Moura, managing director at New Mountain Capital.

“There is a significant opportunity for accelerated growth together, and we look forward to helping Grant Thornton bring its exceptional quality and client service to even more global clients,” added Adam Weinstein, chief operating officer at New Mountain Capital.

The transaction is the first announced by Grant Thornton Advisors since New Mountain Capital’s growth investment in May 2024. In the months since that partnership was finalised, Grant Thornton has accelerated execution of its business strategy with investments in client solutions, service quality, technology and talent.

Upon closing of the transaction, which is expected in the first quarter of next year, subject to regulatory approval, Grant Thornton Advisors and Grant Thornton Ireland will continue to offer clients a full complement of advisory and tax solutions. The independent Grant Thornton Ireland audit business will continue to provide high quality, best-in-class assurance services.

The combined business, which will be led by Grant Thornton Advisors’ CEO, Seth Siegel, will go to market together in all of the territories where each firm currently has a presence. Steve Tennant will assume the role of president of Grant Thornton Ireland and will become a member of Grant Thornton Advisors’ Executive Committee.

Simpson Thacher & Bartlett LLP and William Fry LLP with Arthur Cox LLP are serving as legal advisers to Grant Thornton Advisors LLC and New Mountain Capital. Deutsche Bank Securities Inc. is serving as sole financial adviser to Grant Thornton Ireland, while A&L Goodbody LLP is acting as Grant Thornton Ireland’s legal adviser in relation to the transaction.

About Grant Thornton Ireland

Grant Thornton Ireland is a leading global professional services firm with approximately 2,800 people in offices across the island of Ireland, Bermuda, Isle of Man and Gibraltar. As a member of Grant Thornton International — a global network of more than 73,000 passionate people across more than 149 countries — our people bring you the local knowledge, national expertise and global presence to help you and your business succeed, wherever you’re located.

Our tax, audit and advisory teams have decades of experience working with organizations across our key industries — technology, insurance, asset management, banking, life sciences, aviation, and e-money and payments — as well as in the public sector, delivering solutions that help you realize your ambitions and go beyond the expected.

Innovation and continuous improvement lie at the heart of what we do, and we are recognized leaders in sustainability, prioritizing resilience and long-term value creation alongside ethical practices and positive social impact. Our people invest the time to truly understand your business, giving real insight and a fresh perspective to help achieve the best outcomes for your business. 

About Grant Thornton US

“Grant Thornton” is the brand for two professional-services entities operating across the US: 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. With revenues of $2.4 billion for the fiscal year that ended July 31, 2023, and dozens of offices nationwide, Grant Thornton represents a community of almost 10,000 problem solvers, relationship builders, and industry specialists who know that how we serve matters as much as what we do.

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 LLP and Grant Thornton Advisors LLC serve as the US member firms of the Grant Thornton International Ltd (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.

For further information visit: www.grantthornton.com

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 www.newmountaincapital.com

Contacts

Grant Thornton Ireland

• Fiona MacCarthy

Grant Thornton Advisors and New Mountain Capital

• Jon Rucket
• Daniel Yunger / Nathan Riggs