According to Barclays Capital, U.S. advertising sales may increase 3.5 percent this year as companies increase their national marketing, bringing the total ad spend for 2010 to $167.6 billion. Bloomberg reported the news discovered in a note to Barclays clients from company analyst Anthony DiClemente.

National broadcast spend may jump by 7.8 percent, including Olympic and World Cup coverage. Online ads will increase by 8.9 percent. Prior forecasts anticipated respective increases of 4.8 and 5.7 percent. A large reason for the forecast change was the recent ruling by the U.S. Supreme Court that corporate political spending should have no limits.

“While we expect modest aggregate growth for local media advertising in 2010, we also expect national advertising to outpace the growth of local advertising and take share from local overall,” DiClemente said in the report. With the new forecast, DiClemente anticipated share value increases for Viacom and News Corp.

While still dropping, the newspaper and magazine ad spend losses are not expected to be as precipitous as earlier predicted. Newspaper ad spend is expected to drop 5.8 percent, and magazine ads to decline 3 percent.