Singapore-based Oversea-Chinese Banking Corp (OCBC) is to buy a minority stake in local online brokerage Boom Securities, according to sources. The acquisition - which is expected to be announced next week - follows the purchase of a 10 per cent stake by Australia and New Zealand Banking Group (ANZ) for US$8 million in May. Boom Securities chief executive Mark Duff said the brokerage was in discussions with a strategic investor but declined to reveal the identity. OCBC and ANZ set up a pan-Asian Internet bank joint venture in July which the banks said would partner with Boom Securities as part of its drive to offer a range of online financial services. The joint-venture Internet bank aims to capture about 40 million customers within the next five years, with the two banks investing US$100 million over the next three years. Boom Securities, which was established in 1997, provides trading services for Hong Kong, Singapore and United States shares. Other investors in Boom Securities include the US online investment bank WR Hambrecht & Co, venture-capital firm JF Shea Ventures and local Chinese medicine-producer the Eu family. The introduction of investors such as ANZ and OCBC is expected to enable Boom Securities to expand across the region with the proceeds raised and partnerships with the banks. At the time of ANZ's investment, Boom Securities said it had raised an additional US$8 million to finance expansion. Boom Securities is in the process of buying a seat on the Stock Exchange of Hong Kong. At present, it has to pay part of the fees charged to its clients to brokers who are members of the exchange. This process will end once it acquires a seat.