A sharp drop in manufacturing sales in August is likely to dampen economic growth over the same period, as the outlook for manufacturing sector still remains murky in light of political tensions in Canada's top market, the United States. Statistics Canada said Wednesday the nation's manufacturing sales slipped 0.2% in the last month of summer, reversing three straight months of gains. The figure is below the 1.7% rise in July, and much weaker than a 0.3% increase predicted by analysts. Sales added only $49.5 billion for the month, with sales falling in miscellaneous, food and motor vehicle assembly industries. Meanwhile, the volume of sales, which is used in calculating economic output plunged 0.3%.