This time of year, known as "Golden September, Silver October", is usually a highpoint in sales for the industry, with consumers venturing out to make purchases after having stayed away from showrooms during the stifling summer months.

Sales reached 2.57 million vehicles last month but were still down 6.9% for the year to date at 17.12 million vehicles, according to the China Association of Automobile Manufacturers (CAAM).

"Based on our dealer channel checks, the growth in momentum extended into the October Golden Week, as retail sales exceeded dealers' expectations," said Haitong International analyst Shi Ji.

The Beijing auto show, promotional events and policies enacted by local governments to support the auto sector helped sales growth in September, senior CAAM official Chen Shihua told reporters.

Passenger vehicle sales rose 8% in September. Geely Automobile Holdings Ltd, Great Wall Motor Co Ltd and Toyota Motor Corp were among those that booked double-digit growth.

New energy vehicles did particularly well with sales surging 67.7% to 138,000 for their third consecutive month of gain. NEVs include battery-powered electric, plug-in petrol-electric hybrid and hydrogen fuel-cell vehicles.

NEV makers such as home-grown Nio Inc and Xpeng Inc as well as foreign firms like U.S. leader Tesla Inc are expanding manufacturing capacity in China where the government has aggressively promoted greener vehicles to reduce air pollution.

Tesla on Tuesday cut prices for Model S sedans by around 4% in the United States as well as other key markets like China. Tesla also cut the starting price of its Chinese-made Model 3 sedan this month by about 8% to 249,900 yuan ($36,805).

For trucks and other commercial vehicles, which constitute around a quarter of the overall market, sales surged 40% in September, driven by government investment in infrastructure and as buyers upgraded to comply with tougher emissions rules.

(Reporting by Yilei Sun and Brenda Goh; Editing by Christopher Cushing and Edwina Gibbs)

By Yilei Sun and Brenda Goh