Statistics Canada says wholesale sales, excluding petroleum, petroleum products, and other hydrocarbons and excluding oilseed and grain, fell 0.6 per cent to $82.4 billion in June.
The agency says sales fell in five of the seven subsectors.
Sales in the motor vehicle and motor vehicle parts and accessories subsector fell 2.6 per cent to $14.2 billion as the motor vehicle merchant wholesalers category fell 2.7 per cent to $11.5 billion.
The machinery, equipment and supplies subsector dropped 0.5 per cent to $17.9 billion in June.
In volume terms, wholesale sales fell 0.9 per cent in June.
Statistics Canada started including oilseed and grain as well as the petroleum and petroleum products subsector as part of wholesale trade last year, but is excluding the data from monthly analysis until there is enough historical data.