According to the Paris-based thinktank's latest composite leading indicators (CLIs), economic activity among its 33 associate nations dropped from 103 in July to 102.9 in August, prompting fresh fears that a double-dip recession may be imminent.
"The outlook given by the CLIs for Canada, France, Italy, the United Kingdom, Brazil, China and India points strongly to a downturn," the group stated. "Stronger signals of a peak are emerging in the United States."
Financial experts have expressed concern about a number of countries' ability to respond to a fresh slump, after borrowing significant amounts of funds to pay for emergency stimulus measures.
The news came as figures released by the British Chambers of Commerce suggested that Britain's economic growth slowed considerably during the second quarter of 2010.
By Asim Shah