Google has acquired GrandCentral Communications, a start-up that lets users manage their existing phones and voice mailboxes over the Web as if they were a single account, the company said on Monday.

Financial terms were not disclosed.

Grand Central of Fremont, California is one of dozens of innovative companies that are taking advantage of Web-based software to allow consumers and businesses to make voice calls over the Internet while also working with regular phones.

GrandCentral was founded in late 2005 by Craig Walker and Vincent Paquet.

"You get a single phone number that forwards to all of your phones, giving you one number for life," Walker and Paquet said in a statement on GrandCentral's Web site confirming the deal.

"If you have multiple phone numbers (e.g., home, work, cell), you get one phone number that you can set to ring all, some, or none of your phones," Wesley Chan, a Google product manager, said in a blog post on his company's Web site.

"This way, your phone number is tied to you, and not your location or job," he said.

GrandCentral has been holding public tests of its service for several months. Current GrandCentral customers will continue to have uninterrupted service, Google said.

However, one feature that allowed users to upload their own audio tracks to create ringtones now will be limited to licensed music, GrandCentral said on its own site.

A limited number of invitations to receive GrandCentral unified numbers will be available for users who sign up at http://www.grandcentral.com, it said.