Barclays has agreed to pay $100m (£77m; €90m) to 43 US states and the District of Columbia to settle allegations that it manipulated inter-bank lending rates nearly a decade ago.
New York Attorney General Eric Schneiderman said Barclays is the first of several banks under investigation to reach a settlement with states over the rigging of London Interbank Offered Rate (Libor) and Euribor interest rates.
The UK bank will pay $93.5m in restitution over allegations that it colluded with competing institutions to fix Libor rates at levels that were beneficial to its trading positions between 2005 and 2008. It will also bear the cost of the states' investigation.
Authorities also said that Barclays lowered rates during the financial crisis in order to give the appearance that the bank was not in financial trouble.
The lender received a reported £5.3bn emergency cash injection from Qatar Holding, a subsidiary of Qatar's sovereign investment fund, during the height of the financial crisis.
It allowed Barclays to avoid being semi-nationalised along with Royal Bank of Scotland and Lloyds.
Under the deal struck with US states, the British bank will neither admit nor deny the allegations.
"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," Schneiderman was quoted as saying by Associated Press.
Barclays was fined $290m by the US Commodity Futures Trading Commission in 2012 after it admitted rigging inter-bank rates.
"Barclays is pleased to have resolved the state attorneys' general investigation into Barclays' legacy Libor and Euribor-related activities," a Barclays spokesman was quoted as saying by Reuters.
"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, the UK's second biggest lender by assets, has been hit hard by numerous scandals and has progressively scaled back its retail and investment banking activities in recent years.
Its profits fell by 21% in the first six months of 2016 to £2bn.