In a live interview in front of more than 650 international media delegates, the chairman of the group whose networks includes Starcom MediaVest Group and ZenithOptimedia, will tell media owners they need to adapt their brands to survive.
The comments by Levy, whose group also includes advertising agencies Leo Burnett, Publicis and Saatchi & Saatchi, follow a 5.5% drop in advertising expenditure in the UK last year. This is expected to be followed by double-digit falls in 2009.
Figures published by The Nielsen Company this week show magazines and newspapers have been worst hit by the shifting ad spend in 2008 - down 9% in Europe, 4% in Asia Pacific and 12.7% in North America.
The three-day Congress beginning on 4 May and hosted by the PPA, will feature more than 60 business leaders from around the world attempting to chart the future of an industry dealing with cyclical and structural change.
Jonathan Shephard, chief executive of the PPA, said: "In a time of rapid change, all publishers are reassessing their markets and their strategy, and the congress is the ideal place to be informed, be entertained, to network and to appreciate and learn from real-life examples of success."