In closing arguments capping off a two-week trial in Manhattan federal court, lawyers for Chris Ashton, Rohan Ramchandani and Richard Usher said their clients did nothing illegal by sharing information about the market. The three men, who worked at Barclays Plc, Citigroup Inc and JPMorgan Chase & Co, respectively, have been charged with violating U.S. antitrust law.

The jury is expected to begin deliberating after receiving instructions from U.S. District Judge Richard Berman, who is presiding over the trial.

The outcome is likely to rest heavily on the credibility of Matt Gardiner, a former trader at Standard Chartered, who testified as part of an agreement to avoid prosecution himself. Gardiner said he and the three defendants used an online chatroom dubbed "the cartel" to collude in influencing daily euro-dollar benchmark exchange rates, known as "fixes," in order to benefit their own positions.

The case followed worldwide investigations that resulted in about $10 billion (£7.8 billion) in fines for several large banks. Barclays, Citigroup, JPMorgan, BNP Paribas, Royal Bank of Scotland Group Plc and UBS Group all entered related guilty pleas, and were collectively fined more than $2.8 billion.

Prosecutors said the scheme ran from 2007 to 2013. They have said the New York federal court should decide the case because customers in the state were harmed by the rate-rigging. The defendants came to the United States voluntarily to face the charges.

The defendants' lawyers argued that while the traders shared information about their positions, they decided independently how to use it.

Anjan Sahni, a lawyer for Ramchandani, said Thursday "the cartel" was only one of several joking names given to the chatroom, and that even bank customers who heard it were not concerned.

David Schertler, a lawyer for Ashton, said Gardiner had not pointed to any specific agreement between the four men to rig rates.

"There is really no evidence of any agreement, other than Mr. Gardiner saying, I thought it was understood," he said.

Jurors also heard from University of California-San Diego professor Michael Melvin, a defence witness, who said trading data showed the defendants had not manipulated rates.

"It proves there was no agreement," Michael Kendall, a lawyer for Usher, said of the trading data.

In a brief rebuttal, Bryan Bughman, a lawyer with the U.S. Department of Justice, told jurors the evidence "speaks for itself."

(Reporting By Brendan Pierson in New York; Editing by David Gregorio)

By Brendan Pierson