Weil advises CBIZ Inc on $5 billion sale to Grant Thornton Advisors LLC

Grant Thornton Advisors is using the acquisition to accelerate its expansion into a substantially larger U.S. professional-services platform. The combination adds CBIZ’s established middle-market relationships and capabilities across accounting, tax and advisory services to Grant Thornton’s existing business, while giving the enlarged organisation greater scale for investment in technology, AI, talent and specialist services. The parties expect the combined U.S. business to rank immediately behind the Big Four by revenue.

New Mountain Capital, which has backed Grant Thornton Advisors since 2024, is providing additional equity to support the transaction. Its involvement forms part of a broader growth strategy under which Grant Thornton has become more acquisition focused. The transaction also includes a significant portfolio restructuring: CBIZ’s Benefits and Insurance Services business is intended to be separated following closing, and established as an independent company backed by New Mountain.

Grant Thornton Advisors is being advised by Simpson Thacher & Bartlett, Mayer Brown and Hunton Andrews Kurth.

CBIZ is a national professional-services adviser with a substantial position in the U.S. middle market. The transaction gives the business access to a much larger multinational platform, while retaining its core professional-services capabilities within an organisation expected to have materially greater resources for technology, AI, talent and cross-border service delivery. Management has presented the combination as a way to accelerate CBIZ’s existing strategy while expanding the services and opportunities available to clients and employees.

The agreement also requires CBIZ to navigate a significant corporate transition. On completion it will become wholly owned by Grant Thornton Advisors and cease to be publicly listed, while its Benefits and Insurance Services segment is intended to be separated into a standalone business. CBIZ also negotiated a go-shop period allowing its board and advisers to solicit and evaluate potentially superior proposals before the shareholder vote.

Weil is acting as CBIZ’s legal adviser on the sale. Its disclosed team spans M&A, antitrust, finance, capital markets, tax, executive compensation, governance, regulatory matters, technology and IP, privacy, employment, private funds and real estate. That breadth reflects a mandate extending well beyond negotiating the merger agreement, with specialist legal input required across the consequences of selling and restructuring a large, listed, professional-services organisation.