Google Inc is tapping its huge network of Gmail users and Web surfers to create a Buzz that it hopes will help it catch up with online social networking leaders Facebook and Twitter.

The world's No. 1 search engine yesterday launched Google Buzz, which allows users to quickly share messages, Web links and photos with friends and colleagues directly within Gmail, the company's popular email product.

Also, a new arsenal of products make the new social networking features compatible with mobile devices such as smartphones based on Google's Android operating system.

Google's new technology mimics some of the key features of popular social networking services like Twitter and Facebook, which are increasingly challenging Google for Web surfers' online time.

By integrating Buzz directly into Gmail, Google hopes to jumpstart its social networking push by leveraging the large pool of Gmail users.

"There's always been a giant social network underneath Gmail," said Google Product Manager Todd Jackson at a press event at Google's Mountain View, California headquarters on Tuesday.

Gmail is the third most popular Web-based email in the world, with 176.5 million unique visitors in December, according to comScore. Microsoft Corp's Windows Live Hotmail and Yahoo Inc's Mail were No. 1 and No. 2, with 369.2 million and 303.7 million unique visitors, respectively.

Google will roll out Buzz to Gmail users over the next few days, it said.

Status messages that users publish on Buzz and flag as viewable to everyone will be automatically indexed by Google's search engine and be available within Google's recently launched real-time search results. Google said users can also keep messages private by sharing only with customized groups of friends and colleagues.

Executives said users can easily share content from various Google online properties like photo-sharing service Picasa and video site YouTube.

Content from certain third-party services such as Twitter can also be shared, although users can only view Twitter messages -- or Tweets -- within Buzz and cannot publish new messages to Twitter's service.

Executives said that Buzz is not currently able to display messages that originated on Facebook, the world's No. 1 social network with 400 million active users.

"The fact that Gmail did not connect and allow broadcasts out to Twitter and Facebook could be a real challenge to them," said Forrester Research social media analyst Augie Ray. But he noted that Google's experience serving Web surfers' relevant search results could be a strength for the company in the social media segment as users are increasingly inundated with status messages.

Google has tried to ride the social networking wave before, launching the Orkut social network in 2004. But while Orkut is big in certain overseas markets like Brazil, it has failed to attract as many users as social giants like Facebook and MySpace in the United States.

In building a social network on top of an email product, Google is following in the footsteps of Yahoo, which has taken a similar approach in efforts to keep up with Facebook but has seen lackluster results according to analysts.

Google co-founder Sergey Brin said he was not deterred by other companies' experiences in melding email and social networking.

"I wouldn't discount something because it's similar in the one sense ... to something else in the past that may not be that successful," Brin said on the sideline of the event following the main presentations.

Google appears to be putting a heavy emphasis on mobile and location-based capabilities, weaving Buzz technology into the mobile versions of its flagship website and its online maps products. The company also announced a special mobile application for Buzz that will run on smartphones based on Google's Android software, Windows Mobile and the Symbian operating system.