Five major banks Wednesday agreed to plead guilty to criminal charges and pay more than $5 billion in collective penalties to settle charges their traders routinely manipulated the $5.3-trillion-a-day foreign-exchange currency market for their own profit.

The Department of Justice, the Federal Reserve and other U.S. and European authorities and regulators said corporate units of Citicorp(C), JPMorgan Chase (JPM), London-based Barclays(BCS) and Royal Bank of Scotland(RBS) acknowledged their traders rigged foreign exchange prices of U.S. dollars and euros for several years starting in December 2007.

Outlining what she termed a “brazen display of collusion,” U.S. Attorney General Loretta Lynch said investigators found that traders in the nearly unregulated foreign-exchange market, the world’s largest trading forum, colluded in you-scratch-my-back-and-I’ll-scratch-yours forms of plotting.

The $2.5 billion in criminal fines levied as part of the resolutions represent the largest federal anti-trust penalties ever obtained by U.S. authorities, she said.

“Starting as early as Dec 2007, currency traders at several multinational banks formed a group dubbed ‘The Cartel,’ ” Lynch […]