Economists had expected a drop of 0.5 per cent, according to Thomson Reuters.
It was the third decline in four months.
Sales were lower in eight of 21 industries, accounting for nearly two-thirds of total Canadian manufacturing.
In constant dollar terms sales fell 1.0 per cent, indicating that a lower volume of goods was sold in April.
April sales dropped in every province except Manitoba with nearly two-thirds of the overall decline attributable to Quebec where sales fell 5.4 per cent.
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