Cleveland-based CBIZ has agreed to acquire accounting firm Marcum, making CBIZ the seventh-largest accounting services provider in the U.S. with approximately $2.8 billion in annual revenue.

Concurrent with the closing of the deal, the attest business of Marcum will be acquired by Mayer Hoffman McCann, a Kansas City-based accounting firm with which CBIZ has had an administrative service agreement for over 25 years.

The transaction is valued at approximately $2.3 billion and is expected to be paid half in cash and half in CBIZ stock.

Founded in 1951, New York-based Marcum has 43 offices in major markets across the U.S. and serves more than 35,000 clients. With approximately $1.2 billion in revenue and more than 3,500 professionals, Marcum is the13th-largest accounting firm in the U.S.

"Today marks the most significant transaction in CBIZ's history as we announce our agreement to acquire Marcum," CBIZ CEO Jerry Grisko said in a statement. "At closing, our company will have combined annual revenue of approximately $2.8 billion, more than 10,000 team members and over 135,000 clients. Together, we will provide a breadth of services and depth of expertise that is unmatched in our industry, allowing us to bring a broader array of high-value solutions to our combined client base. This transaction enables CBIZ to strengthen our presence in key markets, continue to attract and retain top talent, and innovate through technology. We are excited about our future together and the opportunities it will provide our people, the solutions we will bring to our clients and the value we expect it will create for shareholders."

The transaction is expected to close in the fourth quarter of 2024 subject to the approval of CBIZ stockholders, the approval of Marcum's partners and other customary closing conditions.