Grant Thornton Advisors has agreed to acquire CBIZ in a cash deal valued at more than $3 billion, according to the companies. The transaction would take CBIZ private and marks a major move in the U.S. professional services market.

The companies said the combination would make Grant Thornton the fifth-largest provider of professional, tax and advisory services in the United States. That ranking highlights the scale the firm expects to gain through the acquisition.

CBIZ is known as a professional services adviser, and the planned takeover signals continued consolidation across accounting, tax and consulting-related businesses. A larger combined platform could strengthen Grant Thornton’s position as firms compete for corporate clients and broader service offerings.

The deal was announced on Wednesday, with both sides outlining the transaction as an all-cash agreement. Further details on timing and closing conditions were not included in the brief announcement.