SHANGHAI, Sept 4 (Reuters) - China stocks closed lower on Friday after a sharp overnight selloff in Wall Street, with the benchmark Shanghai index posting a weekly loss after a five-week winning streak.

** The blue-chip CSI300 index fell 1.0% to 4,770.22, while the Shanghai Composite Index ended 0.9% lower at 3,355.37.

** The tech-heavy start-up board index slipped 0.5%, and the STAR50 index dropped 0.9%.

** For the week, CSI300 shed 1.5%, while SSEC lost 1.4%.

** Overnight, Wall Street's main indexes marked their deepest one-day dives in months as investors dumped the high-flying technology sector, while economic data highlighted concerns about a long and difficult recovery.

** The U.S. selloff dented sentiment in the A-share market, as foreign investors sold via the Stock Connect after such corrections, said Zheng Zichun, an analyst with AVIC Securities.

** Refinitiv data showed investors on Friday sold a net 4 billion yuan ($584.56 million) worth of China stocks via the Stock Connect linking mainland and Hong Kong, which allows foreign investors access to the country's onshore equities.

** Leading the declines, the CSI300 consumer staples index dropped 2.1% on worries about lofty valuations.

** Apple Inc's suppliers also fell, after the iPhone maker's shares slipped 8% overnight.

** But Zheng was optimistic about the long-term outlook for A-shares, citing low valuations compared with their U.S. peers and Beijing's continued policy support as it needs a robust market to finance the country's tech industries.

** Bucking the broad retreat, China's semiconductor firms climbed on Friday on report of new policies to prop up the chip sector. [nL4N2G10LO}

** The A-share market will remain rangebound for the moment, and investors could pay attention to pro-cyclical sectors with low valuations, analysts at Huaan Securities noted in report. ($1 = 6.8428 Chinese yuan) (Reporting by Shanghai Newsroom; editing by Uttaresh.V)