Statistics Canada says wholesale sales fell 0.6% in July to $80.2 billion, led by a drop in the personal and household goods subsector.
The agency says sales fell in five of seven subsectors, which represented 63% of wholesale sales.
Sales of personal and household goods fell 2.6% in July to $10.8 billion as the textile, clothing and footwear industry fell 13.2%.
The building material and supplies subsector saw sales fall 1.7% to $12.8 billion for the month as sales of lumber, millwork, hardware and other building supplies lost 2.8%.
Meanwhile, sales of machinery, equipment and supplies rose 1.6% to $17.0 billion.
Overall, sales in constant dollar terms fell 1.0% in July.