Reuters Messenger has 300,000 subscribers of which 70,000 are active. Around 1,000 new users join each week.
The information provider pioneered an IM service for the financial community in 2002, although it has been plagued by technical problems.
The service now allows users to swap sensitive price information confidentially, build chat rooms based on their investment interests, and invite contacts from inside or outside their own company.
But Reuters bosses were keen to distance themselves from the teen culture that dominates chat rooms.
"When we say chat rooms, we do not mean some place where teenagers swap stories about Star Wars or worse," said Reuters chief executive Tom Glocer.
Reuters Messenger is designed for financial services and even allows traders to send a 'bear' or 'bull' symbol to denote trading activity, or select from a range of specialised 'emoticons' such as a man weeping in despair. This is presumably reserved for Black Mondays.
IM systems in finance came under scrutiny in the US in the late 1990s because it was noticed that traders were communicating without an audit trail. As a result regulations now stipulate that all IM 'chats' are saved for later scrutiny in the same way as phone calls.
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