Wholesale sales are down because of sluggish sales for basic materials.
Official figures show seasonally adjusted wholesale sales declined 0.3% in the three months to September, led by falls in sales for agricultural supplies, pharmaceuticals and furniture.
That was offset in cars and motor-vehicle parts.
The seasonally adjusted value of total wholesale stocks rose 0.8% to $9 billion.
The survey monitors the level of activity in the wholesale trade sector, which supplies retailers.