Weil, Gotshal & Manges and Simpson Thacher have picked up lead roles as Grant Thornton Advisors has agreed to acquire professional services firm CBIZ for $5bn, in a deal that will create one of the largest professional services providers in the US.
Mayer Brown and Hunton Andrews Kurth are also involved on the deal, which will see Grant Thornton buy the NYSE-listed CBIZ in an all-cash transaction, supported by a new equity investment from New Mountain Capital.
Weil is advising CBIZ, led by corporate department chair Michael Aiello, who is ranked in the Legal 500 Hall of Fame for both M&A: large deals and telecoms and broadcast: transactions. The firm’s team also included M&A practice co-head Matthew Gilroy, also a Legal 500 leading partner for large deals, and M&A partner Iliana Karaoglan. All partners are based in New York.
Leading Simpson Thacher’s team for Grant Thornton is New York M&A partner Ben Schaye, who is highly experienced in the accounting sector.
Hunton Andrews Kurth is also advising Grant Thornton, led by Matthew Bosher, who co-heads the firm’s corporate, securities and government investigations practice group, and works out of the firm’s Washington DC and Richmond, Virginia offices.
The team from Mayer Brown also advising Grant Thornton on the deal includes M&A partner Paul Theiss, who works out of the firm’s Chicago and New York offices, New York office corporate and securities co-lead Camila Panama, and New York corporate and securities partner Brian Hirshberg.
All three firms acting for Grant Thornton on the deal were involved in the growth investment made by New Mountain Capital in Grant Thornton in 2024, with Simpson and Hunton advising New Mountain Capital, and Mayer Brown advising the partnership board of Grant Thornton.
Partners who also advised on the previous deal include Simpson Thacher’s Schaye, Hunton’s Bosher, and Theiss and Panama from Mayer Brown.
The combined platform will span more than 20 countries and territories, with nearly $7.5bn in revenue. Under the terms of the deal, CBIZ shareholders will receive $55 per share.
Commenting on the transaction, Grant Thornton Advisors CEO Jim Peko said: ‘By combining our multinational platform with CBIZ’s strong market presence, we’re broadening our ability to support businesses through every stage of growth — from early development to global scale. Together, we’ll bring the quality, scope and capabilities clients need to navigate an increasingly complex and rapidly evolving business environment.’
The transaction is expected to close in Q4 of this year, subject to approval by CBIZ shareholders, regulatory approval, and other customary closing conditions.
