Urban Life, claimed to be the biggest initiative of its kind by the UK newspaper group, will regularly monitor the views of 3,000 readers on a wide range of topics from work to fashion and TV.
The agency's task will be to convince advertisers as well as agency planners, creatives and media buyers that Urban Life shows Metro is in tune with its 1.3 million readers.
The account, which was previously handled by Banc, moves after talks between Metro executives and a number of agencies, plus a number of strategy meetings with Barrett Cernis. Media buying remains with MediaVest.
The assignment will evolve into an ad campaign promoting the paper, despite doubts whether a freesheet needs to advertise itself.
However, Justin Cernis, the managing director of Barrett Cernis, said: "We have not been appointed just to launch Urban Life, and one of the first things we will be doing is to define the paper's advertised role."
Barrett Cernis becomes the third agency, after Banc and Mustoe Merriman Levy, to have handled Metro's account since the paper's launch in March 1999. It has editions in London, Birmingham, Manchester and Edinburgh.
Karen Wall, the head of marketing for Metro, commented: "Barrett Cernis has impressed us with its approach to our business. In a short space of time, it has developed a great understanding of the Metro brand and built an excellent relationship with us."