ZenithOptimedia also revised its forecast for global ad spending this year to a 9.9% decline, from its July forecast of an 8.5% decline.
In making the revisions, ZenithOptimedia pointed to a worse than expected first half this year.
For example, the 15 largest media companies in the world had an average revenue decline of 13.1% in the first half, according to the report.
“We are still confident that the second half of the year will be much less painful for the ad market than the first half, and expect the market to hit bottom before the end of 2009,” ZenithOptimedia said in the forecast.
In the U.S., ad revenue is projected to be down 12.9% this year and down 4.4% next year, according to the report.