"The possible fine that DNB has been notified of is not related to any suspicions of money laundering or complicity in money laundering, but rather what (the FSA) considers to be inadequate compliance with the anti-money laundering rules and legislation," DNB said.
The bank will now examine FSA's preliminary report and submit a response, it said.
"The fight against financial crime is an important part of DNB's corporate responsibility, and it is a task on which the company spends considerable resources," the bank said.
The indicated fine corresponds to around 0.7% of DNB's annual revenue.
The FSA did not immediately respond to a request for comment.
(Reporting by Victoria Klesty, editing by Terje Solsvik)