Morgan Stanley agreed to pay a US$10 million (S$ 13.7 million) fine to settle a US regulator's allegations that for more than five years its anti-money laundering programme failed to appropriately monitor tens of billions of dollars in transactions that ran through brokerage accounts.

The alleged shortcomings related to wire and foreign currency transfers, including transactions that involved countries known for having a high risk of money laundering, the Financial Industry Regulatory Authority (Finra) said in a statement on Wednesday.

The firm's insufficient monitoring lasted from January 2011 until at least April 2016, the regulator said.

Finra also said Morgan Stanley failed to adequately supervise customers' penny stock trades, despite the fact that clients had about 2.7 billion shares in their accounts that led to US$164 million in stock sales.

Morgan Stanley neither admitted nor denied Finra's allegations.

"We are pleased to have resolved this matter from several years ago," Morgan Stanley spokesman Susan Siering said in a statement.

"We continuously work to strengthen our controls and have been recognised by Finra for the extraordinary steps we have taken to expand and enhance our anti-money laundering programme."

BLOOMBERG