OTTAWA (Reuters) - Canadian manufacturing sales dropped by 2.6 percent in July, the most in more than a year, as annual auto plant shutdowns cut sales of cars and motor vehicle parts, Statistics Canada said on Tuesday. The decline was the biggest retreat since the 4.2 percent plunge seen in February 2016. Analysts in a Reuters poll had predicted a 1.6 percent dip. Sales fell in nine of 21 industries, representing 57 percent of the manufacturing sector and in volume terms fell by 1.4 percent. The transportation equipment industry posted a 13.8 percent decline, the largest since May 2009. Statscan said the auto plant shutdowns were longer and more concentrated in July compared with previous years. Food industry sales dipped 0.9 percent. The wood products and primary metals sectors showed strength, gaining by 2.3 percent and 1.9 percent respectively. (Reporting by David Ljunggren; Editing by W Simon)