Grant Thornton’s U.S. arm agrees to acquire CBIZ Inc. in a roughly $5 billion transaction, one of the largest professional services acquisitions in more than 25 years, according to multiple reports. The deal is described as valuing CBIZ at about $5 billion, with at least part of the consideration characterized as cash by some outlets. The acquisition is expected to expand Grant Thornton’s footprint in the U.S. accounting and advisory market, where competition is dominated by the “Big Four” firms—Deloitte, EY, KPMG and PwC. One report says the combined company would become the fifth-largest professional services provider in the United States. Another source notes that CBIZ shares rise following the announcement, including a reported 17% jump, reflecting investor reaction to the proposed transaction. Overall coverage frames the move as part of broader consolidation in the professional services industry and positions Grant Thornton as a larger challenger to the established large-firm incumbents. The reports present consistent deal size and strategic intent, with varying emphasis on market impact and stock reaction.