By Aruna Viswanatha 

WASHINGTON--Five global banks agreed to pay more than $5 billion in combined penalties and will plead guilty to criminal charges to resolve a long running U.S. investigation into whether traders at the banks colluded to move foreign currency rates for their own financial benefit.

Four of the banks, J.P. Morgan Chase & Co., Barclays PLC, Royal Bank of Scotland Group PLC, and Citigroup Inc., will plead guilty to conspiring to manipulate prices in the $500 billion-dollar-per-day market for U.S. dollars and euros, authorities said.

The fifth bank, UBS AG, received immunity in the antitrust case, but will pay a fine and plead guilty to manipulating the Libor benchmark for violating an earlier accord meant to resolve those allegations of misconduct.

The size and scope of the resolutions reflect authorities' attempts to crack down on what they called "breathtaking" misconduct, with some of the largest fines levied to date by the Justice Department for antitrust violations. Prosecutors also took the unusual step of ripping up a prior agreement over subsequent violations and extracted the first criminal guilty pleas from big U.S. banks in decades.

"These unprecedented figures appropriately reflect the conspiracy's breathtaking flagrancy, its systemic reach and its significant impact," Attorney General Loretta Lynch said.

Yet the Justice Department didn't announce charges against individuals at any of the banks, with Ms. Lynch saying only "that investigation is ongoing." New York's financial regulator said it required Barclays to fire eight employees in connection with its resolution.

And in a sign of how prosecutors have tamped down the impact of criminal guilty pleas, the banks said they expected little business disruption from pleading guilty.

Some banks blamed the conduct on a small group of traders and suggested the problems weren't systemic throughout the firm.

"The lesson here is that the conduct of a small group of employees, or of even a single employee, can reflect badly on all of us, and have significant ramifications for the entire firm," said J.P. Morgan Chief Executive James Dimon, who added the bank is working to fortify its controls.

Authorities said euro dollar traders at the banks, who were self-described members of "The Cartel" communicated through coded language in an online chat room to coordinate attempts to move rates set at 1:15 and 4 p.m.

Officials said a 19-month investigation in which FBI agents conducted 175 interviews and reviewed a terabyte of trading data showed traders withholding bids or offers to avoid moving the rate in directions that would hurt open positions held by other members of the group, in violation of antitrust laws.

Members of the group discussed whether to allow one Barclays trader to join the chat room and ultimately decided to let him in for a "1 month trial," but advised him: "mess this up and sleep with one eye open at night," according to the New York Department of Financial Services.

The fines, which include penalties from the Federal Reserve and other regulators, come on top of a combined $4.3 billion many of the same banks paid in November to resolve similar charges from U.S. and U.K. regulators.

Bank of America Corp. will also pay a $205 million penalty to the Fed to resolve the regulator's foreign exchange probe. Bank of America didn't face similar action from the Justice Department.

Citigroup, which was accused of being involved in the misconduct from December 2007 through January 2013, is paying the largest criminal fine of $925 million, in addition to a Fed penalty of $342 million. The other banks were accused of engaging in the conduct for various periods within that time frame.

"The behavior that resulted in the settlements we announced today is an embarrassment to our firm, and stands in stark contrast to Citi's values, " Chief Executive Michael Corbat said in a news release, adding its internal investigation has so far resulted in nine terminations.

Under its settlement with the Justice Department, J.P. Morgan will pay a fine of $550 million, while the Fed penalty is $342 million. The bank has previously reserved for the settlements.

One bank, Barclays, pulled out at the last minute of the November settlement with regulators, and is now paying $2.38 billion to the Justice Department, the Federal Reserve, the Commodity Futures Trading Commission, the New York State Department of Financial Services, and the U.K. Financial Conduct Authority.

It also agreed that its foreign exchange trading and sales practices violated its 2012 Libor agreement, and agreed to pay an additional $60 million penalty.

Prosecutors said UBS would plead guilty in connection with similar violations. They said UBS engaged in deceptive foreign exchange trading and sales practices after its 2012 agreement, including by adding undisclosed markups to certain customers' transactions in which traders and sales staff told customers there were no markups added.

One UBS trader also engaged in the same collusive behavior in the euro and dollar market, but the bank wasn't charged over that conduct because it had obtained immunity by being the first bank to report the possible antitrust violations.

The five banks will be under a three-year period of probation, overseen by the court. The plea agreements will require the banks to implement compliance programs to prevent and detect attempts to manipulate rates and provide an annual report on that progress to the government. Under agreements with regulators, the banks are already obligated to more broadly improve compliance and controls.

Prosecutors said the fines are tied to evidence they have to prove a profit to the bank or loss to others from the manipulation. Ms. Lynch said the Justice Department's fines would go to the U.S. Treasury.

--Emily Glazer contributed to this article.

Write to Aruna Viswanatha at aruna.viswanatha@wsj.com

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