Citigroup Inc. (C) and JPMorgan Chase & Co. (JPM) are putting their top London currency dealers on leave after regulators probing the manipulation of foreign-exchange rates started investigating the traders’ use of an instant-message group... --- Regulators are focusing on an instant-message group the traders set up to share information about their positions and client orders over a period of at least three years, four people with knowledge of the probe said this month. The roster of banks in the group changed as the men moved firms and also included Barclays Plc (BARC), Royal Bank of Scotland Group Plc and UBS AG (UBSN), three people with knowledge of the communications said.

Investigators are weighing whether the messages amounted to attempts to manipulate the market, two people said. The five firms account for about 47 percent of the $5.3 trillion-a-day foreign-exchange market, according to a May survey by Euromoney Institutional Investor Plc. (ERM) Two other traders, who weren’t part of the conversations and who asked to not be identified because they do business with those involved, said that they and others in the market referred to the message group as “The Cartel.”

"The Cartel"