The car maker said in a statement it sold a total 389,500 of its VW-brand cars in August, an increase of 9.5 percent over the year-earlier figure.

That brought overall sales so far this year to 3.34 million units, an increase of 12.1 percent year-on-year, the statement said.

"Deliveries of our VW brand cars are continuing to develop favourably," said marketing and distribution chief Christian Klingler.

"For the first time in the January-August period, we sold more than three million cars. Nevertheless, we're monitoring the global automobile markets very closely."

All regions showed strong growth, with sales in North America rising 12.6 percent in the eight months since January, followed by Asia/Pacific with an increase of 14.3 percent and European sales up 9.1 percent.

In China, VW's biggest market, unit sales jumped 11.3 percent to 1.02 million cars.

In the home market of Germany, VW posted a 9.0-percent increase in sales to 394,700 vehicles.