Google has announced the purchase of Marratech AB, a Stockholm-based developer of video-conferencing software. The move pushes Google further into the sphere of collaborative work tools.

Marratech said yesterday that it will continue to support its customers and resellers. Google said Marratech's engineers will remain in Sweden and continue to develop the desktop conferencing software. Terms of the acquisition were not disclosed.

Google yesterday announced a major upgrade of its Google Apps suite.

Marratech produces cross-platform conferencing software that lets people enjoy audio and video conferencing, application sharing and instant messaging. The client software runs on Windows 2000 or XP, Mac OS X 10.4, or versions of Linux including Mandriva 10.2, SuSE 9.1 or Fedora Core 2, and requires a Pentium III or G4 processor running at 1GHz or faster. There's also a server component, Marratech Manager.

Marratech says it's cheaper for companies to buy its server-based system than to use web-based conferencing services that charge by the minute.

For Google, the acquisition is the latest in a series of moves taking it into the sphere of collaborative working. It already offers communication tools including the GoogleTalk messaging and VoIP (voice over IP) application, and a white-label version of its email and calendaring tools for small businesses.

It also offers a white-label version of its Google Docs and Spreadsheets online productivity software, called Google Apps. That service will soon also incorporate a module for building presentations, following Google's acquisition Wednesday of Tonic Systems Inc., allowing it to compete in more areas with Microsoft Corp.'s thick-client Office suite.