OCBC is said to have made a binding bid for a family-run bank in Hong Kong, in what could be its biggest acquisition in history.

Wing Hang Bank has a market value of US$4.6 billion (S$5.8 billion). If the deal goes through, it could be the largest acquisition by a local bank since DBS bought Hong Kong's Dao Heng Bank for US$5.8 billion in 2001.

OCBC is said to have offered less than the two times book value that Wing Hang was seeking, according to a Bloomberg report on Friday which cited anonymous sources.

When asked to confirm the acquisition on Friday, OCBC declined to comment.

The bank gets nearly two-thirds of its revenue from Singapore and is expanding overseas in countries such as Malaysia, Indonesia and China.

Wing Hang has a network of 70 branches spanning Hong Kong, Macau and mainland China.