Canada's seasonally adjusted Ivey purchasing managers' index plunged to 53.7 in September from 58.0 in August. Analysts had expected the index to decrease to 54.0.
A reading above 50 indicates a rise in the pace of activity, below 50 indicates a contraction in the pace of activity.
The supplier deliveries index was up 49.8 in September from 48.2 in August, while employment index climbed to 57.1 from 56.3.
The prices index was fell to 64.4 in September from 66.3 in August, while inventories increased to 52.1 from 42.4.