Six of the world's biggest banks will pay $5.8 billion and five of them agreed to plead guilty to charges tied to a currency-rigging probe as they seek to wind down almost half a decade of enforcement actions.

Citicorp, JPMorgan Chase & Co., Barclays Plc and Royal Bank of Scotland Plc agreed to plead guilty to felony charges of conspiring to manipulate the price of U.S. dollars and euros, according to settlements announced by the Justice Department in Washington Wednesday. The main banking unit of UBS Group AG agreed to plead guilty to a wire-fraud charge related to interest-rate manipulation. The Swiss bank, the first to cooperate with antitrust investigators, was granted immunity in the currency probe.

The four banks that agreed to plead guilty to currency charges are among the world's biggest foreign-exchange traders. They were accused of colluding to influence benchmark rates by aligning positions and pushing transactions through at the same time. Traders who described themselves as members of "The Cartel" used online chat rooms to discuss their positions before the rates were set and suppress competition in the market, the Justice Department said.