Roberts was director of comms at the Labour Party between 2010 and the May general election. He was previously a journalist for 20 years, working at regional newspapers, the Press Association and finally as political editor of the Daily Mirror.
He will take up his post on 2 November with a remit of delivering corporate comms to commercial and political audiences, as well as designing comms programmes for the corporation’s key services in the Square Mile and across London.
Roberts said: "I am delighted to taking up this role and look forward to working on a range of comms issues with my new colleagues."