AOL has released its new AIM Pro instant messaging application. 

The free program targets business users by offering integration with Microsoft Outlook and one-click access to the WebEx Communications online conferencing tool. It also has enhanced security features.

Around 135 million workers worldwide use instant messaging services, according to market research firm The Radicati Group.

AOL claims that about 14 million subscribers of the consumer-oriented AIM application use the tool for business. 

Internet measuring firm ComScore Media Metrics puts the worldwide number of instant messaging users at 339 million. 

MSN Messenger leads the pack with about 204 million subscribers, followed by Yahoo Messenger with 78 million and AIM with 64 million unique monthly users.

The AIM Pro launch illustrates the increased level of competition in the enterprise instant messaging space.

IBM offers an enterprise grade application with Lotus Sametime, while Cisco offers instant messaging as part of its Unified Meetingplace suite of unified messaging offerings. 

Microsoft said earlier this week that it would partner with Nortel Networks to integrate instant messaging with traditional telecoms services. 

Enterprises have had a rocky relationship with instant messaging. Users often install the applications without the IT department's authorisation, subjecting businesses to potential security and data retention issues.

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