Employees of Credit Suisse First Boston, Goldman Sachs, JP Morgan Chase, Lehman Brothers, Merrill Lynch, Morgan Stanley, Salomon Smith Barney and UBS Warburg will use the service to communicate across their organisations and with customers.
The service, which was supplied by Communicator Inc, also gives access to authorised content and applications.
IM has been popular in the consumer sphere but until now has not been widely adopted by businesses. It typically consists of software that puts a window on the desktop into which text is typed and instantly transmitted to recipients. A feature of IM is that it informs the user whether specified individuals are online at that time.
Research by IDC found that about 70% of firms have employees using IM software, but this is largely for personal use. Software such as that provided by Communicator allows businesses to build large-scale "gated" communities with access and rights governed by the corporate directory and 128-bit encryption.
Communicator's Hub IM offers unified identity management, controlled access to content and applications, interoperability between corporate directories and features that enable compliance with audit and regulatory requirements.
David Bradshaw, an analyst at Ovum, said, "IM clearly has its uses. Its value lies in the speed of response it allows as well as the possibility of handling multiple responses. The risk is that a user can inadvertently send inappropriate information which cannot be recalled.
"We will see a growth in IM, but closely associated with business applications - we are seeing a higher degree of verticalisation with business apps being tailored for specific industry needs."