The fall was in stark contrast to the global advertising spend, which increased 5.7 per cent, according to new figures from Nielsen.
In an increasingly polarised field, emerging markets saw spending rocket, led by an 18.2 per cent gain in Latin America, while Europe fell 3.2 per cent overall.
Revenue dropped in 16 out of the 36 global markets – the first significant decline since the third quarter of 2009. Total expenditure for the quarter was $127bn (£81.5bn).
Declines in spending for the fast moving consumer goods category in Europe and North America, and the continued decline of newspaper ads, contributed to slower growth in these regions.
Randall Beard, head of advertiser solutions for Nielsen, said: “Compared to the 8.9 per cent growth rate in the first quarter of the year, there was definitely some slowdown. But, based on the global economy and the financial problems many countries have experienced, the overall figure is still great news.”