Global vehicle sales continued on a collision course with year-ago levels, as total vehicle deliveries in August dropped to 5.49 million cars and trucks, a mere 3.4% ahead of year-ago.

It was the fifth consecutive month of declining performance, compared with prior year, falling in line with an earlier Ward’s forecast that fourth-quarter results may dip below like-2009.

August was the second-worst month in 2010 for vehicle sales – only February’s 5.3 million deliveries were lower – and represented an 8.3% month-to-month decline compared with July. It also was the fourth month to fall short of the 6 million-unit mark.

Vehicle sales through the year’s first eight months rose to 48.7 million units, for a 16% gain on year-ago. However, current trends continue to fall in line with earlier Ward’s forecasts pointing toward zero year-over-year monthly sales growth by October.

Related document: World Vehicle Sales Summary

North America played a role in the poor August showing, registering the region’s first year-over-year decline since November. However, the 17.2% downturn was expected, as last August’s sales soared above trend thanks to the U.S. Cash-for-Clunkers scrappage program.

The region’s September sales, on the other hand, are expected to track well ahead of prior-year, which saw deliveries fall dramatically with the end of government-sponsored incentives.

Asia/Pacific growth of 17.1% in August held steady with July’s rate (17.0%) but was significantly lower than the region’s growth for the year’s first half, which jumped 39% ahead of like-2009.

The Asia/Pacific region accounted for 43.5% of world sales in August and 43.4% of all deliveries year-to-date.

Europe year-over-year sales slipped just 1.1%, an improvement from July, which saw deliveries decline 8.4% compared with a scrappage-bolstered year-ago. The region still was able to grab a 20.4% share of the global market.

South America’s largest economy, Brazil, saw vehicle sales rise 7.5% in August. But credit strong growth in the smaller markets, including Argentina (up 44.8%) and Venezuela (up 38%), for the region’s 13% gain on year-ago, good for a 5.7% share of worldwide sales for the month.