Google's new instant messaging client could force existing instant messaging (IM)networks to open up, research firm Gartner said in a research note.

Google on Wednesday launched a beta of its Google Talk instant messaging and VoIP client. The software uses the open XMPP (Extensible Messaging and Presence Protocol) that allows its users to communicate with other messaging systems that use the same protocol, such as Jabber and Apple's iChat.

"This structure could bring about IM interoperability among the major players if Google gains enough market traction to force changes," said Allen Weiner, Gartner's research director for media and search.

In the US alone about 80 million individuals use instant messaging, with approximately half of them signing up to AOL's network, according to data from Gartner.

The leading instant messaging applications from AOL, MSN and Yahoo! lack interoperability, preventing users of AOL IM from contacting MSN Messenger or Yahoo! Messenger and vice versa.

The lack of interoperability forces users to sign up to several networks and has given rise to so-called unified messaging clients such us Trillian.

If Google succeeds in collecting a large user base on its open network, this could increase the pressure on the closed clients to embrace open standards.

In the press release about the new service, the search giant said that it believes in open communication models and that it wants to enable users to talk on any network.

Without interoperability, the current beta of Google Talk has little to offer users, Gartner noted. The software should add support for emoticons and webcams to increase its appeal. Google could also use the tool to serve users with personalised content.