Auto sales in Canada dropped in August, the third month in a row that the country saw fewer cars and trucks sold, according to figures released by Statistics Canada on Tuesday.

Dealerships sold 137,937 vehicles in August, a drop of 2.3 per cent compared to July, Statistics Canada said.

"This third consecutive monthly decline was due entirely to falling sales of passenger cars," the national statistical agency said in a news release.

Passenger car sales slid 4.2 per cent in the month, to 73,484 vehicles. North American-built autos were entirely responsible for the fall with sales down 6.8 per cent in August.

After two consecutive monthly declines, overseas-built passenger car sales edged up 0.4 per cent.

August's negative showing represented the third consecutive month in which Canada's auto sales fell compared to the previous month.

Sales of new cars and trucks fell 0.8 per cent in July and one per cent in June compared to the month before.

May the only month in 7 to buck downward trend

In fact, except for a small sales gain in May, Canada has experienced negative growth in this sector for six of the past seven months.

Thus, from January's monthly sales of 153,231, Canada's new car and truck sales fell 10 per cent to August's total.

North American carmakers have suffered through a miserable period since January. Rising oil prices combined with heightened economic uncertainty have conspired to hurt the sector's ability to sell new vehicles.

Worse, the August figures did not include any of the economic fallout from September's meltdown among financial service companies, a factor likely to harm next month's sales results even further.