Barclays' investment arm has been fined $13.75 million (£9.3m) by US regulators following allegations that it allowed customers to make unsuitable mutual fund deals over a five year period.
The bank will pay $10m in compensation to the customers affected, and a further $3.75m fine to the US Financial Industry Regulatory Authority (Finra).
Despite agreeing to the settlement, Barclays has not admitted any wrongdoing over the case.
During the five year period, the bank is accused of not making customers aware of the costs involved with switching between mutual funds. Figures show that more than 6,000 switches took place in that time. Finra said customers lost a total of $8.6m as a result of switching.
The regulator also said that Barclays processed more than 1,700 transactions that went against their customers' investment targets or were more risky than the investors' wanted.
In November, Barclays was fined £72m in the UK for failing to conduct proper checks on some of its wealthiest clients because it 'did not want to disturb them'.