Alter Surety Group, Inc.

Markel's primary business is property and casualty insurance. The company focuses primarily on specialty lines, ranging from areas such as executive liability to commercial equine insurance. The acquisition of Alterra in 2013 added substantial reinsurance operations, which now account for a little over 10% of premiums. The company uses capital generated by its insurance operations to buy noninsurance operations in diverse areas, such as bakery equipment manufacturing and residential homebuilding.

Listed as a carrier partner of BrokerTech Ventures.