O2, Britain's biggest mobile operator, is to announce tie-ups with MySpace and Facebook to offer its subscribers access to the popular social networking sites on the move.

The deal with MySpace — which is owned by News International, parent company of Times Online — will enable subscribers to track and contribute to their MySpace pages on the move without having to sit at a personal computer.

It will be available from November.

Separately, the group, which is owned by Telefónica, of Spain, has said it is to join the crowded fixed-line internet market with the launch of O2 Broadband.

The mobile group, which has 17.8 million UK mobile customers, is to go head to head with players including Carphone Warehouse and Virgin Media with the launch of a new broadband service that will be available to existing pay monthly mobile customers from as little as £7.50 a month.

It will launch on October 15.

In the UK most people who want a mobile handset already have one, so the main mobile operators — Vodafone, O2, Orange, T-Mobile and 3 — are being forced to chase after each other's customers.

The launch into broadband by players including O2 and Vodafone is in large part a defensive move, aimed at helping them to cling onto subscribers.

Tie-ups with cult internet names such as Facebook and Google constitute another strand in their efforts to lock in subscribers.

Recent research by Nielsen/NetRatings, the analyst, showed that Facebook received 6.5 million unique visitors in August, compared with MySpace's 6.4 million.

Both sites, the research found, are visited by one in every five Britons with online access.

They hope that such applications will help to stimulate update of more lucrative "data" services.

At present, despite efforts by the mobile operators, the bulk of mobile revenues are still drawn from plain voice and text messaging.

O2 recently stole a march over its rivals by securing a deal with Apple to market exclusively the iPhone in the UK.

Competition between the operators to secure the tie-up was the fiercest since the auction for next-generation "3G" licences in 2000.

O2 is the latest mobile operator to tie up with a social networking site. Orange has already done a deal with Bebo, and Vodafone is working with MySpace.

J-P Sanchez, of MySpace Europe, said: "For MySpace users their profile is at the heart of their online and offline live — this deal with give them anytime, anywhere access."

O2 first indicated its intentions to move into the fixed-line market last year, when it snapped up Be, the niche broadband player, in a £50 million deal.

The launch of its service has been delayed several times.

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