It's official: Google will sell its own mobile phone in an effort to protect its online advertising empire as people increasingly surf the Web on handsets instead of personal computers.

The phone announced Tuesday had been widely anticipated since Google handed out the device, called the Nexus One, to its own employees three weeks ago.

Google hadn't announced the pricing of its self-described "super" phone during the first few minutes of a press conference.

The Nexus One escalates Google's budding rivalry with former Silicon Valley ally, Apple Inc., which has sold more than 30 million iPhones in the past 2 1/2 years.

Apple announced a deal Tuesday to buy mobile advertising service Quattro Wireless to counter Google's proposed $750 acquisition of Quattro rival AdMob.