Customers of wireless service provider Three will now be able to access Wi-Fi for free (down from £2 earlier) in the London Underground public metro system, thanks to a partnership between Three and Virgin Media.

Customers of Three will get free Wi-Fi on the London Underground system starting from the last week of July. Virgin Media will provide Wi-Fi service to the London Underground system, as a part of its contract with Three.

Three's latest initiative puts the wireless service provider into the league of other London Underground free Wi-Fi service providers such as Vodafone, O2 and EE.

"Giving our customers access to free WiFi on the London underground is another step towards them being able to enjoy the benefits of being connected no matter where they are," said Danny Dixon, Three's director of customer strategy, in an official press release.

Customers of Three can make use of the company's InTouch application to make calls over Wi-Fi during their travel in the London Underground metro system.

Three had launched the standalone InTouch application for its customers, in June this year.

Now, with the company partnering Virgin Mobile, to offer free Wi-Fi in London Underground, customers can not only make and receive calls and text messages, but will also be able to connect to the internet and browse websites and social networking sites for free, even when on the move.

Virgin Media has been offering standalone Wi-Fi services to its customers ever since the 2012 London Olympics. The company's Wi-Fi network is currently active across 137 stations covered by the London Underground metro system.

Virgin Media has also made public its intention to bring more London Underground metro stations under the ambit of its free Wi-Fi network coverage.

These stations are: Shepherds Bush, West Brompton, Harrow on the Hill, Bow Road, Ealing Broadway, Hammersmith and Edgware Road.

With the addition of these stations, a total of 144 London Underground metro stations will be offering free Wi-Fi coverage to customers of both Three and Virgin Media.

"We're delighted that another mobile operator is on board because it means more of our customers benefit from live travel information, news and social media throughout the majority of our stations," said Gareth Powell, director of Strategy and Service Development for London Underground.

With Three and Virgin Media jumping into the 'free Wi-Fi on the London Underground Metro System' bandwagon, almost all of UK's major service providers offer free Wi-Fi within the London Tube transport network.

"Virgin Media also offers a Pay As You Go service with daily, weekly and monthly passes5, giving Tube passengers a range of options about how to get online underground," stated Virgin Media, in the press release.