China's auto sales fell in July for the fourth straight month, an industry group said Tuesday, as economic growth slows in the world's largest car market.

Vehicle sales in the country totalled 1.50 million units last month, down seven percent from 1.62 million a year earlier, according to figures provided by the China Association of Automobile Manufacturers (CAAM).

It was the fourth consecutive month in which sales had decreased and the fall was the sharpest of the period, CAAM data showed, accelerating from a 2.31 percent drop in June.

Production fell to 1.52 million units from 1.72 million a year earlier, plunging more than 11 percent year-on-year, according to CAAM.

Economic growth hit a 24-year low last year, expanding 7.4 percent amid a steady slowdown from years of double-digit expansions.

Growth in gross domestic product has decelerated further this year, expanding 7.0 percent in each of the first two quarters.

Car plate restrictions in some major cities to ease traffic gridlock and stock market volatility this year have also hit demand.

The Shanghai stock index plunged more than 30 percent over three weeks from a June 12 peak before rebounding on aggressive government support measures.

China's overall auto sales reached 23.49 million vehicles last year, jumping 6.9 percent from 2013 but falling short of CAAM's growth target of 8.3 percent for the year.

CAAM in July lowered its estimate for this year's increase to "around three percent" from the previous seven percent, after sales in the January-June period gained just 1.43 percent year-on-year.