AOL has released a beta tool that links its Instant Messenger (AIM) software with Microsoft's Outlook e-mail application. It allows Outlook to be used to see if people are online and hold chats.

The program is available for free download from the website for users of AIM version 5.9 or higher who use Outlook 2002 or 2003. Microsoft already offers integrated messaging features in Outlook through its own IM services.

The new tool, called AIM Sync, allows users to add contacts from Outlook to their AIM buddy list and matches e-mail addresses with AIM screen names. It then shows the "presence", or availability of contacts to chat online, by placing icons in the e-mail, address book and phone list views of Outlook. Users who click on an icon can launch a chat or access the buddy's phone number and send a text message to a mobile phone by SMS.

The integration of presence into e-mail applications underscores the need for users to be able to easily switch between instant messaging (IM) and e-mail functions depending on the urgency of information, AOL said.

The beta tool is also a way for AOL to gain more users for its IM service, since users can invite Outlook contacts who do not have AIM to join up.

Consumer IM accounts are expected to reach some 240 million by 2008 with an increasing amount of services hooking into enterprise applications, according to a recent report from researcher IDC.

Although major consumer IM service providers Microsoft, AOL, and Yahoo have historically gone head-to-head in the battle for users, the companies have recently taken steps to provide more integration between their applications.

Last year, Microsoft announced that its Live Communications Server 2005 would allow users to exchange messages with users of public IM networks for Yahoo, AOL and MSN.