The US is already seeing a slowdown in advertising spending, according to research released on Tuesday that showed cutbacks by big carmakers and media groups are weighing on broadcasters and newspaper publishers.

“The ad market remains stalled and is being engulfed by the spreading pessimism about general economic conditions,” said Jon Swallen, senior vice-president for research at TNS media intelligence, which tracks advertising spending for 2.8m brands in 20 media categories.