Text Size Published: Tuesday, 17 Dec 2013 | 6:33 AM ET
The source said JPMorgan's decision was unrelated to the foreign-exchange (FX) probes which first surfaced in June, noting that this had been under review at the bank since even earlier this year.
"This has always been about more than FX," the source said, adding that the casual nature of online chat rooms increased the potential for "inappropriate" remarks to be made.
Bilateral online chats between JPMorgan traders and traders at other financial institutions are under review, while external chats between JPMorgan staff and clients will still be permitted, the source said.
Deutsche Bank has prohibited its foreign exchange and fixed income staff from using online chat rooms, and UBS banned the use of multibank and social chat rooms at its investment banking division.
Traders at banks and financial institutions often communicate with each other online via third-party services including Bloomberg and Thomson Reuters.