The agency says higher sales in the agricultural supplies industry and the food industry were largely behind the increase.
It says that in volume terms, wholesale sales were up 2.4 per cent in May.
All subsectors reported higher sales in May compared with April, with the miscellaneous subsector and the food, beverage and tobacco subsector accounting for more than 70 per cent of the growth.
Nine of the provinces reported higher wholesale sales in May, with only Prince Edward Island posting a decrease.
Meanwhile, after a 0.5 per cent rise in April, inventories were unchanged at $61.8 billion in May.
On a year-year basis, total wholesale sales were up 0.8 per cent from $49.9 billion in May 2012.