The Bank of China (BOC) is awaiting approval from its Beijing headquarters to increase the size of its $2 billion note issue after a huge response from potential investors.
According to a circular issued by China's State Administration of Exchange Control, which took effect in June, the amount raised from debt issues by mainland bank overseas branches has to be reported to the headquarters.
The bank's original issue of a five-year floating rate certificate of deposit attracted subscriptions of $9 billion from more than 60 institutions.
Banking sources believe the issue will at least be doubled, although a $5 billion total has not been ruled out.
A BOC spokesman said the arranger, China Development Finance Company, was discussing the final size of the offering with BOC but declined to comment on when a decision would be made.
It is believed the delay was caused by the BOC having to report to its headquarters for approval.