• by David Goetzl  @dgoetzl, July 6, 2011

GroupM has reduced its forecast for 2011 ad growth globally, but the WPP arm still has that rate topping the U.S. GroupM now projects 4.8% worldwide, compared to 3.8% domestically. The U.S. accounts for about 30% of global spending.

The group said the Japanese earthquake and roiling Middle East have caused it to revise downward its global forecast by a full percentage point.

Looking at 70 countries, it now projects volume to be $506 billion in spending.

Next year with a London Olympic games and U.S. elections, GroupM is projecting a 6.8% increase that would be up more than $34 billion.

In the U.S., 2011 spending should hit $148 billion, then rise another 4.2% next year, which would still keep the U.S. market's share around 30%, though it would be a bit lower than this year.

GroupM London-based Futures Director Adam Smith and Chief Investment Officer Rino Scanzoni released the new data culled from WPP sources in advertising and market research.

"It's highly unusual for natural disasters to measurably impact the totality of global advertising," Smith stated. "However, the earthquake and subsequent tsunami in Japan was of this rare scale."

The tragedies were so severe GroupM cut its Japan forecast from 3% growth to a 5% decline, a drop of $4 billion, taking about 1% out of global spending. In the Middle East, turmoil has caused an estimated $1.2 billion drop.

This year, digital advertising should be 17% of global dollars and the sector is growing at up to 16% a year.

"Digital advertising spending accounts for 20% and more of measured advertising in countries where it is most developed, but it still has real growth potential, even in those nations," Smith stated. "A recurring theme from such countries is the commercial utility of behavioral targeting and Web video, even among traditional 'brand' or 'awareness' advertisers."