Barclays has agreed to pay a $100 million (£77m) settlement over claims made by 44 US states related to rigging the Libor rate.
The New York attorney-general, Eric Schneiderman, said government and not-for-profit organisations had been defrauded of millions of dollars through the manipulation of the interest rate by Barclays employees.
In July, four former Barclays bankers were jailed for between 33 months and six years for their part in the scandal.
The Libor - London Interbank Offered Rate - is the interest rate used by banks to determine the cost of lending to each other. It is responsible for trillions of dollars worth of transactions.
Eric Schneiderman said: "There has to be one set of rules for everyone, no matter how rich or how powerful, and that includes big banks and other financial institutions that engage in fraud or impair the fair functioning of financial markets."
He added: "Government entities and not-for-profit organisations in New York and throughout the US, among others, were defrauded of millions of dollars when they entered into swaps and other financial contracts with Barclays without knowing that Barclays and other banks on the USD-Libor-setting panel were manipulating Libor."
Responding to the settlement, Barclays said: "Barclays is pleased to have resolved the state attorneys' general investigation into Barclays' legacy LIBOR- and Euribor-related activities," a spokesman for the bank said. "We believe this settlement is in the best interests of our shareholders and clients, and allows us to continue to focus on the future and serve our clients."
Barclays has already paid out $453m in fines and settlements relating to the Libor scandal. But other banks have been hit far harder by the fallout. Swiss banking giant UBS has paid out $1.5bn.