Cisco has announced that it plans to buy instant messaging platform vendor Jabber, a move that could heighten its battle with Microsoft over the collaboration and office communications market.

Terms of the deal, which is expected to be completed in the first half of Cisco's fiscal 2009, were not disclosed.

Jabber, based in Denver, has developed a ‘carrier-class’ platform based on open standards that can work across multiple messaging systems, such as AOL Instant Messenger, Google Talk, Yahoo Messenger and Office Communications Server.

Cisco intends to use it to become "the interoperability benchmark in the collaboration space", Cisco senior vice president Doug Dennerline said.

The pending Jabber deal comes just a few weeks after Cisco took another shot across Microsoft's bow by announcing plans to buy PostPath, maker of email and calendaring software.