NEW YORK: Total US advertising expenditure fell 4% to $37.4bn in the first quarter new data has shown, with spending by the ten largest advertisers declining even more steeply.

Jon Swallen, chief research officer at Kantar Media North America, advised that the figures were skewed by comparisons to last year and the $600m of incremental spend that had been generated by the Sochi Olympics.

"Excluding the impact of special events, core ad spending measured by Kantar Media was down about 2% in the period," he said.

"Even after taking into account assumptions about the growth of spend on other unmonitored media, it has been a relatively slow start for the ad market in 2015."

The other unmonitored media no longer includes paid search, which Kantar Media included in its analysis for the first time. Ad spending here, which reflects text ads on the Google and Bing search engines, rose 7%.

Kantar continues, however, to exclude two fast-growing ad formats – video and mobile – from its figures for online display advertising which declined 8.7%, in part because consumers are shifting usage to mobile.

Overall, 16 of the 21 individual media types monitored by Kantar Media had lower ad spending in the first quarter.

Spending on network TV was down 9.2%, but was flat if the effect of the Winter Olympics was removed. Spot TV fell 6.8% and Syndication expenditures 4.9%.

Cable was one of the few growing areas, along with Spanish-language TV. The former rose 4.1%, aided by an increase in the amount of available paid ad time as networks packed more spots into programming to help offset lower audience ratings.

Spending by the ten largest advertisers declined 10.6% to $3.7bn in the quarter, and among the top one hundred – a diversified group accounting for two-fifths of all measured ad expenditures – budgets fell 6.6%.

The decline was especially pronounced at Procter & Gamble, the world's largest advertiser, where a 24.5% decrease was registered in investments in TV, online display and print media. This, said Kantar, was "consistent with recent company statements about shifts in their advertising budgets".

Data sourced from Business Wire; additional content by Warc staff