New York—Total U.S. ad spending is projected to increase 4.2% this year, according to a new forecast by TNS Media Intelligence.

For the first half of the year, ad spending will increase by 3.6%, followed by a gain of 4.7% during the second half, according to the forecast.

Ad spending for the 2008 Summer Olympics and the elections will help offset the effects of the weakened economy, said Jon Swallen, senior VP-research at TNS.

The strongest growth will come from Internet advertising, which is projected to grow by 14.4% over last year. Spot TV will increase 9.9%, cable network TV will grow by 5.0%, broadcast network TV will increase 2.7% and spending on b2b magazines will decrease by 0.1%, according to the forecast.

—Kate Maddox