Korea Development Bank (KDB) is moving to take over three financial firms from Hyundai Group, which is selling its affiliates as part of restructuring to improve capital flow, market sources said Monday. Sources in the investment banking sector said KDB, the business group's main creditor, has started due diligence on Hyundai Securities Co. The securities firm holds a 100 percent stake in Hyundai Savings Bank Co. and Hyundai Asset Management Co., which have all been put up for sale