The cable operator is to provide millions of commuters and visitors with WiFi internet access at up to 120 Tube stations across London.
This will become available to Tube passengers from July at more than 80 stations, coinciding with major events such as the London Olympics and Queen's Diamond Jubilee. The WiFi-enabled stations will rise to 120 by the end of the year.
During an initial period the service will be offered for free to all customers, but it will later be made available as part of Virgin Media's broadband and mobile subscriptions.
Virgin Media customers will be able to access the WiFi depending on their subscription, while everyone else will need to sign up to pay-as-you-go plans or other commercial models.
All customers will be able to access live TfL travel information for free via a new online portal.
"It's vital that we harness the massive opportunities stemming from the digital revolution, by creating a vibrant, world class industry to attract investment and create jobs for Londoners," said Boris Johnson.
"Millions of passengers will now be able to connect to their work, friends or access the latest news and travel information whilst on the move. This is a fabulous new and free resource which will be in place from this summer when London is being showcased on a global stage and playing host to millions."
The cost of providing WiFi at stations will be covered by Virgin Media's commercial contract. The firm said that the launch is in response to feedback from Tube travellers that they would find WiFi access useful and it would make their journeys more pleasant.
Virgin Media chief executive Neil Berkett added: "With the eyes of the world on London this summer, we'll be showing off our capital as a leading connected city on the global stage.
"We're putting the power of Virgin Media's fibre optic network in the hands of millions of Londoners, commuters and visitors and are delighted to be launching WiFi for free throughout summer 2012 and beyond.
"We'll help people make the most of the city and will continue to evolve the service, ensuring everyone can benefit from a service London will be proud of."
London Underground director of strategy Gareth Powell said that the move is about upgrading the Tube to "make it fit for the 21st Century".
He said: "This latest innovation is great news for Tube customers, who now have access to emails, web and social media underground for the first time. It's also delivered at no cost to fare payers and taxpayers.
"Today, TfL provides a wealth of free live travel information, via our website and through the many excellent travel apps now available.
"WiFi on the Tube means our customers can now get the latest live travel information and check how services are running, on the move and underground, where and when they need it."
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