Revenue is expected to grow 3.8% to $149bn (£91bn) this year, marking a decline from the 10.3% increase last year, according to Informa.
Commentators are expecting 2012 to bring more positive growth thanks in part to the London 2012 Olympics and the US Presidential elections.
Last year’s growth was driven by improving consumer and corporate confidence and the World Cup. The increase followed an 8.1% drop the previous year.
Latin America is expected to become big growth region because of the World Cup finals in 2014 and the 2016 Olympics being held in Brazil.
Adam Thomas, Informa media research manager says: “The fairly conservative increase expected in 2011 is driven by a perception that the global economic recovery is not yet on a solid footing. But this is not the only factor limiting the ad market. Audiences are being fragmented by greater programming choice. This has given advertisers greater channel choice and enabled them to negotiate lower rates.”
The Informa figures calculate net advertising and reflect only the revenues received by the channels and networks.