The lucrative account, worth the 'upper end of six figures' according to a source, will see Edelman implement a worldwide campaign as Telnic builds up to the launch of its .tel domain name in December.

The firm's website allows users to store all their contact details in one virtual place. It then acts as a net-based directory, easily accessible from mobile devices.

'We are not doing any traditional advertising,' said Justin Hayward, comms director at Telnic. 'Instead we are looking at online and broadcast campaigns to help explain this way of using the internet.'