The London Underground railway is to get Wi-Fi coverage in time for this summer's Olympic Games after the railway signed a deal with Virgin Media.

Under the terms of the agreement, Virgin Media will put Wi-Fi hotspots within 80 stations by this summer, with 120 stations to be fitted out by the end of the year. The network has 270 stations in total.

During the initial phase, access to the service will be free for all users, but will become chargeable after the Olympics have finished, although Virgin customers will continue to receive free access. It will continue to offer free live travel information via a new online portal for all users.

The announcement follows trials of Wi-Fi coverage in several underground stations - although that was carried out by Virgin's rival company, British Telecom.

The service is being delivered at no cost to London Underground.