China's vehicle sales may fall short of a forecast of 10 million units this year as slowing economic growth and a slumping stock market undermine consumers' purchasing power.

"It is possible that we can't make it to 10 million (units) this year," Zhu Yiping, senior deputy secretary general of China Association of Automobile Manufacturers, said in a telephone interview with reporter. "The economic fundamentals have an impact on all aspects including vehicle sales."

China's vehicle sales dropped for the first time in 3 years in August, according to the association. China's key CSI 300 Index has fallen by over 60 percent this year as economic growth has slowed for four straight quarters.

Shanghai Volkswagen Co's sales fell 27 percent last month, the biggest decline among the top three car makers in the country.