China's vehicle sales fell 3.8 percent in August to 2.1 million units from a year earlier, continuing the downward trend seen in July in the world's largest vehicle market, said the China Association of Automobile Manufacturers on Tuesday.

The fall in August came in the wake of a 4.02 percent fall in July and was the third so far this year, but the association is maintaining its estimate of 3 percent growth for the year.

Total vehicle sales in the first eight months of the year stood at 18.1 million, up 3.5 percent from the same period last year, according to the association.

Xu Haidong, an assistant to the organization's secretary-general, said the decline in the two months is the result of a combination of factors, including slower overall economic growth and stock market declines.

"These have dented consumer confidence, although there is little fundamental change in the automotive market," said Xu.

But he is optimistic about the future, saying there is no doubt about the upward trend in the decade to come.

"As you can see, many international carmakers from Toyota to BMW are expanding their production capacity here in China."

Despite the long-term prospects, the dented confidence among consumers has taken its toll on the passenger car market, which accounted for the lion's share of total vehicle sales in the country.

Sales of sedans, SUVs and MPVs each fell in the month, ranging from 3.4 percent to 13.6 percent. Minivans saw 5.1 percent growth, but their volume has been negligible in the segment.

Despite the fall in July and August, passenger car sales totaled 15.19 million units from January to August, maintaining meager growth of 2.6 percent year-on-year.

But the fierce competition had cut Chinese carmakers' market share by 2.8 percentage points to 38.2 percent by the end of August.

Commercial vehicles have maintained their growth so far this year. With 1.1 percent growth in August, their sales in the first eight months of the year reached 2.9 million, up 8.7 percent year-on-year.

New energy vehicles sales are also slowing compared with previous years. Their sales, which consist of electric cars and plug-in hybrids, reached 101,000 units in July, up 49.5 percent from the same month last year.

The growth rate from January to August stood at 88 percent, bringing sales in the eight-month period to 601,000 units, even though the Chinese government raised the threshold of its financial stimulus for such vehicles from early June.