Riggs Bank, which stands accused of helping the former Chilean leader Augusto Pinochet evade efforts to seize his assets, is to be sold.
Riggs has long been an active bank in the diplomatic community.
PNC Financial Services Group will pay $779m (£420m) in cash and shares for the bank's parent Riggs National.
The Federal Reserve recently told Riggs to do more to prevent money laundering.
In May, Riggs was fined $25m for allegedly failing to report suspicious transactions, some of which might be connected to terrorism financing.
The fine was over Riggs handling of cash transactions in Saudi-controlled accounts that were under investigation by anti-terrorism officials.
The bank stands accused of helping Gen Pinochet hide up to $8m.
Riggs responded to the fine by inviting advisors to start arranging a sale the head of the family that controls Riggs stepped down from the board.
The bank also responded by pulling back from some of its international engagements.
Riggs has long been an active bank in the diplomatic community and it is the largest bank in the Washington area.
The PNC agreement stipulates that Riggs will pull out of all its diplomatic and international businesses.
The sale of Riggs National comes just a day after a US Senate report alleged that its bank helped former Chilean leader Augusto Pinochet hide up to $8m.
The report alleges the bank set up several accounts for Gen Pinochet while he was under house arrest in the UK in 1998.
Riggs Bank on Thursday said it took compliance with regulations seriously and would address the issues raised by the report.
Gen Pinochet's son has dismissed the findings as "lies".