Three months after announcing its new Voice technology, Google is now giving official invites to people who had signed up for the beta version of its VOIP service to try it out. The Google VOIP service is an enhancement of the technology from GrandCentral - a company that was taken over by Google for a supposed $50 million, in 2007.

The Google Voice service, which till Thursday was accessible only by GrandCentral users, has now been extended to all those people who had 'pre-registered for invitations' for the trial. However, Google, the Mountain View-based Internet giant, is yet to disclose the availability of a full public version of the service.

The new service provides users with a single telephone number and voice mail box for their home and cell phones, and allows them to make and manage their phone calls. Moreover, the Google Voice users can also avail the benefits of free domestic calls; paid international calls; and automatic transcription of voice mails.

About the expanded availability of the Google Voice service, Google said that it is still inviting the future users to apply for the service, and expects to spread it out to more invitees on June 25.

On its blog, Google said: "Once you receive your invitation, just click on the link and follow the instructions to set up your new Voice account."