American Financial Group Inc. has agreed to acquire Shaker Heights, Ohio-based ABA Insurance Services Inc. from American Bankers Mutual Insurance Ltd. for about $28 million in cash.

The transaction is expected to close in the fourth quarter, following customary regulatory approvals.

After the closing, ABA Insurance Services will continue to operate under the ABA Insurance Services brand and will become a specialty property and casualty business unit of Great American Insurance Group.

ABA Insurance Services provides directors and officers and other complementary insurance solutions for banks, small businesses and nonprofit organizations.