Shares in Oversea-Chinese Banking Corp fell to a near four-week low in Singapore yesterday amid concern it may pay too much to take over Wing Hang Bank. Wing Hang's biggest shareholders agreed to "engage exclusively" with Singapore-based OCBC until January 31 to complete the terms of a possible offer, Hong Kong's second-largest family-run lender said in a statement to the city's stock exchange on Monday. No financial details were disclosed. OCBC chief financial officer Darren Tan yesterday said the firm's key aims were tapping into the offshore yuan market and building a customer franchise in Hong Kong, Macau and Taiwan. Wing Hang, which has 70 branches in Hong Kong, Macau and on the mainland, has a market value of HK$36.2 billion. Wing Hang and OCBC, Southeast Asia's No2 lender, had reached a consensus on a price range for the takeover, a person familiar with the matter told the South China Morning Post . If the final price is set at 1.8 times Wing Hang's book value - as speculation has suggested an offer would come in at less than two times book value - OCBC would have to pay HK$36.7 billion for its 307.4 million shares, translating into HK$119.52 per share. The parties were following procedures to keep the regulators informed, and OCBC was investigating its financing options for the purchase, the person said. "After the progress on price negotiations and the likelihood for the deal to be completed, Wing Hang chose to give an exclusive window to OCBC for a possible takeover," the source said. Wing Hang is believed to have attracted interest from a range of suitors, including Agricultural Bank of China and China Minsheng Bank. Firms outside banking were also rumoured to be interested, including the mainland's Anbang Insurance. OCBC's status as a big regional bank had convinced the Hong Kong lender that efforts to reach a deal could proceed smoothly, the source said. Hong Kong's family-controlled banks, which have long felt the squeeze from bigger rivals such as HSBC and Bank of China, are attracting takeover interest as the city's role in cross-border financing expands. OCBC shares yesterday fell 1.21 per cent to close at S$9.75 (HK$59.47), after dropping to as low as S$9.73. "The market is still thinking about how OCBC is able to extract value" out of Wing Hang, said Wee Siang Ng, an analyst at Maybank Kim Eng Securities. "Wing Hang Bank is a decent bank, but it would be challenging to make a difference in that competitive marketplace."