Further queries are being raised about the wisdom of OCBC's proposed acquisition of an Asian bank, a report says.

OCBC’s proposed acquisition of Wing Hang Bank is in danger of being a repeat of fellow Singapore-headquartered DBS's purchase of Dao Heng Bank that took "painful restructuring", the Business Times publication said, citing a report by Macquarie.

BT quoted the bank’s 85-page report as saying:  "Watching all of history repeat itself.” The report has cautioned local Singaporean banks against making the kind of errors it says international banks have made in mergers and acquisitions in recent times.

OCBC is parent of Bank of Singapore, the private bank that was bought from ING in early 2010.

Macquarie views the Wing Hang deal to be a negative one for OCBC. "It does not play into 11, and it adds material pressure on OCBC's capital ratio,” the report is quoted as having said.

Credit Suisse warned in early July that shares of Wing Hang Bank, the Hong Kong firm that is being acquired by Singapore-headquartered Oversea-Chinese Banking Corp, could drop by as much as 40 per cent if OCBC is unable to secure enough stock to take the business off the stock exchange. OCBC bid $5 billion for Wing Hang in early April this year. That offer was accepted by 50.4 per cent of the bank’s stock.

OCBC Bank's Cheong Choong Kong, meanwhile, is retiring as chairman 31 August. Dr Cheong, who had held the role for 11 years, will be succeeded on 1 September Ooi Sang Kuang, a former deputy governor of Bank Negara Malaysia (BNM) and currently OCBC's non-executive lead independent director, OCBC said in a statement.