• by Joe Mandese  @mp_joemandese, December 5, 2011

Worldwide ad spending will expand 4.7% to a total of $427 billion, according to estimates released this morning by Interpublic's Magna Global unit at the annual UBS media conference in New York. That estimate is down slightly (-0.5%) from the +5.2% forecast Interpublic published in June 2011, "due to the softening of some markets in the second half of the year."

Not surprisingly, TV and the Internet, especially, are teh big drivers among the major media categories.

TV, which Interpublic called, "an unexpected winner in 2010," rising 12.7% in total spending despite the absence of a big sports or political stimulus, will take in 41.0% of global ad spending.

"The big winner of 2011, however, was Internet media," Interpublic says, estimating that total Internet ad spending rose 16.9% to $78.5 billion.

"While display subcategories increased +15%, paid search reaped the benefits of usage growth and algorithm improvements to reclaim its position as the largest digital revenue driver (+19%)," Interpublic noted, adding, "Within display, online video continues to show impressive growth (+58.5%), reaching $4.7 billion in revenues. Pre- and mid-rolls in online videos now generate 6% of total Internet advertising revenues and one percent (1.1%) of global advertising revenues. Even more than online video sharing specialists, TV broadcasters offering free, ad-funded online 'catch-up' of long-form, full-length episodes are driving category growth."