NEW YORK: US adspend growth is slowing as large advertisers become more conservative with their budgets in difficult economic conditions, Kantar Media has said.

New data from the research firm shows that expenditure in the world's biggest ad market grew by 1.5% over the first nine months of 2011, when compared with the same period a year ago. But annual growth for the third quarter reached just 0.4%, as the economic news on both sides of the Atlantic worsened.

Kantar also found that the nation's 10 largest advertisers cut their spending by -1.4% year-on-year, with the biggest of all, FMCG giant Procter & Gamble, declining still further (-5.6%).

Moreover, three of the top 10 firms – General Motors (GM), Verizon Communications and News Corp – reduced their expenditure by 10% or more over the same period.

Commenting on the figures, Jon Swallen, senior vice president for research at Kantar Media North America, said: "During Q3, an expanding number of the largest marketers became even more conservative with their ad budgets and these reductions have neutralized the healthy spending growth occurring among mid-sized advertisers."

By category, automotive outperformed the rest of the market on $9.9bn spent, with ad expenditure up 7% year-on-year despite GM's budget cuts.

Local services (up 7.2% to to $7.1bn) came second, with "miscellaneous retail" – retail stores excluding the department store, home furnishing and building supply segments – rising 3.2% to $6.7bn to take third place.

Of the 10 largest categories, personal care products enjoyed the biggest annual increase, rising 7.6% to take seventh place on $4.8bn.

However, telecoms, in fifth place, suffered the largest adspend decline, down -4.9% to $6.4bn. Again, large firms in the category proved to be a drag on growth, with AT&T and Verizon's adspend dropping -3.5% and -18% year-on-year respectively.

In terms of media, TV expenditure across all categories was up 2.3% from the first nine months of 2010, while internet was up 2.8%.

Warc's latest International Ad Forecast (November 2011) predicts an increase in all-media adspend for the US of +2.5% in 2011.

Data sourced from Kantar; additional content by Warc staff