Lockton Inc. of Kansas City today said it has acquired the international insurance arm of Alexander Forbes Ltd., for about $170 million. Lockton has been working with the Forbes unit, Alexander Forbes International Risk Services, of London for about a decade to provide international services for its U.S. customers. Presuming regulators in the United Kingdom, U.S. and South Africa approve, the transaction is expected to close in October. The transaction will make Lockton the world's largest privately owned independent insurance broker as well as its 10th largest insurance broker of any kind. Seller Alexander Forbes Ltd., Africa's largest independent pension fund administrator, said it sold the international brokerage to focus on its home market and planned to use the proceeds of the sale to reduce debt.