Rosen will be responsible for accelerating the mobile operator’s revenue growth and product innovation by building closer relationships with the brand, publisher and agency community.
He will be based in London and report to Telefónica’s chief executive of innovation and digital disruption Stephen Shurrock.
Rosen replaces Shaun Gregory who was appointed as CEO of Exterion Media, the company previously known as CBS Outdoor, in March.
Prior to joining Joule in 2012, Rosen was the founder and head of AKQA’s global mobile practice, where he worked on campaigns for brands such as Nike, Coca-Cola and Volkswagen.
He also served as managing director of Associated Newspapers’ interactive subsidiary Greenland and started his mobile career in the 1990s on the Orange marketing team.
Telefónica grew its revenues by 1.3 per cent year on year to €12.7bn in the three months to June. Operating income rose 10.4 per cent to £2.1bn in the quarter.
In February Telefónica closed its Telefónica Digital sub-brand as part of a restructure of the business aimed at simplifying decision-making and cutting costs.