Oversea-Chinese Banking Corp has extended exclusive talks to buy Wing Hang Bank beyond a January 31 deadline, Wing Hang said yesterday. Sources said that while the banks had largely agreed on financial terms, OCBC was seeking a go-ahead from the Hong Kong Monetary Authority before announcing a deal. An announcement could come as early as next month, they said. Singapore-based OCBC said on January 6 that it was in talks to buy Wing Hang, which has a market value of HK$33.4 billion, and that it had exclusive rights to negotiate with Wing Hang's biggest shareholders until January 31. Those exclusive rights had been extended to March 3, Wing Hang said. OCBC is attempting Hong Kong's biggest banking acquisition since 2001 as chief executive Samuel Tsien accelerates expansion overseas. A purchase of Wing Hang would leave Hong Kong with two family-owned lenders, after Chong Hing Bank agreed last year to be bought by the mainland's Yue Xiu. A deal would represent OCBC's biggest acquisition to date, giving it a much sought-after gateway to the mainland and helping it bridge the gap with bigger Singaporean rival DBS, which operates Hong Kong's fifth-biggest bank. Talks between the companies were centring on a valuation of almost 1.9 times Wing Hang's book value, one source said. OCBC is in talks to first buy the 45 per cent of Wing Hang held by chairman Patrick Fung's family, its affiliates and Bank of New York Mellon, before making a general offer for the rest of the bank, according to the January 6 statement. Wing Hang closed 1 per cent higher in Hong Kong yesterday, valuing the bank at 1.64 times book value. Yue Xiu's US$1.5 billion deal to buy a majority stake in Chong Hing Bank, announced in October, was approved by the HKMA on January 9. OCBC had obtained commitments for a bridge loan, primarily to show regulators that it had enough funding to buy Wing Hang, the sources said.