The media-buying division of Publicis Groupe will announce today at the annual UBS media conference in New York that it has dramatically reduced its prediction for worldwide ad spend growth in 2009 from 4% to a fall of 0.2%.
It had forecast 4% growth in October but is now predicting a 0.2% decline, with the greatest downward revisions in North American and European markets.
In the UK alone, ZenithOptimedia has cut £427m off its earlier forecast, predicting that the total ad market in the UK will be worth £12.8bn in 2009.
Ad expenditure in North America is set to fall 5.7% next year compared with 2008 and in Western Europe ZenithOptimedia cut its forecast from 2.6% growth to a fall of 1%.
It has revised its expectations of growth in central and eastern Europe from 12.7% to just 1.5% amid concerns about the economic stability of Hungary, Turkey and the Ukraine.
However ZenithOptimedia still believes developing advertising markets will lead growth in the long term, forecasting that they will contribute up to 89% of all ad expenditure growth between 2008 and 2011.
Latin America is still seeing healthy growth with an expected 14.9% 2009 gain, thanks to 30% growth in Brazil.
Internet advertising will grow fastest at 17.7% in 2009, wile newspapers and radio adspend are expected to decline.
ZenithOptimedia said that as a result of the economic crisis it will now start reviewing its figures monthly instead of quarterly.
It expects a mild recovery to begin in the third quarter of 2009.