Four of Scotiabank's commodity subindexes fell, with the biggest declines in the oil and gas sector as well as in agriculture.
Forestry was the only subindex to show an increase between July and August while mining and metals was down slightly.
Scotiabank says international oil prices have been pulling back since June because of less concern about the risks to oil supplies from Iraq and Libya.
It says Brent crude — an international benchmark — hit a low of US$96.65 in September, down from US$115 per barrel on June 19. Brent was trading at US$96.71 a barrel on Monday.
Scotiabank's oil and gas index dropped 9.7 points, agriculture fell 6.7 points, and metal and minerals slipped 0.4 points. Forest products rose 1.3 points.
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