Punjab National Bank said on Wednesday that it had detected "fraudulent and unauthorized" transactions worth about Rs 11300 crore at one of its branches in Mumbai.
The bank said in a statement the transactions were "for the benefit of a few select account holders with their apparent connivance" and that "based on these transactions other banks appear to have advanced money to these customers abroad."
The bank did not disclose the people involved but said it had reported the deals to law enforcement agencies and would decide whether it faces any liability arising out of the transactions later. PNB shares fell as much as 5.7 percent in early trading on Wednesday.
"In the bank these transactions are contingent in nature and liability arising out of these on the bank shall be decided based on the law and genuineness of underlying transactions," PNB said, without giving further details.