GOOGLE ADDED a social networking feature to its Gmail e-mail service this week, to take on market leader Facebook.

The program, called Google Buzz, allows users to share photos and clips from its YouTube video site and updates from Twitter. It also lets users comment on other subscribers’ posts.

“This is another very compelling evolution,” Google co-founder Sergey Brin said at a launch event in Mountain View, California, this week. “You have the meeting of social communication and productivity.”

Google hasn’t been able to transfer its dominance in internet search to e-mail and social networking.

Gmail is the world’s third most used e-mail service and Google’s Orkut social site ranks fifth, according to researcher ComScore. Facebook, the top social networking service, updated its site last week to make it easier to check messages, notifications and friend requests.

Buzz, which has a post feed similar to those on Facebook and Twitter, will be available on mobile devices including Apple’s iPhone and those that run on Google’s Android software.

The program automatically includes contacts whom a user frequently e-mails. Posts can be private or public.

The company rolled out Buzz to Gmail accounts over the last few days and plans eventually to offer it to businesses and universities using Google Apps.

Google also introduced an updated version of its Mobile Maps, which can show the location of people posting items on Buzz. The location feature also finds businesses and other landmarks to help users identify where they are.

Some of Gmail’s original engineers now work at Facebook. They left Google to start a company called FriendFeed, which Facebook bought last year.

Facebook said this month it had 400 million users worldwide, double the number a year ago.

Mr Brin declined to comment on current talks between the company and the Chinese government, except to say it is “hard to operate” there under the circumstances.

Google said last month it was targeted by “highly sophisticated” cyber attacks aimed at obtaining information on Chinese human rights activists.