SHANGHAI, Sept 3 (Reuters) - China stocks ended lower on Thursday, as investors pulled out of high-flying consumer firms on worries over lofty valuations, while Sino-U.S. tensions also dented sentiment, outweighing optimism stemming from upbeat services sector data.

** The blue-chip CSI300 index fell 0.6%, to 4,817.10, while the Shanghai Composite Index eased 0.6%to 3,384.98.

** The tech-heavy start-up board ChiNext slipped 0.9%, while the STAR50 index dropped 1.5%.

** Selling intensified in the afternoon, as investors retreated from leading consumers firms following stellar gains in recent weeks.

** The CSI300 consumers staples index ended down 0.4%, with bellwether Foshan Haitian Flavouring slumping 6.5% after hitting an all-time high in morning trade.

** The CSI300 healthcare index shed 0.6%, with Zhangzhou Pientzehuang Pharmaceutical pulling back from a record high to close 2.5% lower.

** "We had been strongly recommending consumer firms including liquor makers and flavouring firms for quite a long time, though we now no longer sing a song of praise to record-breaking consumer players," analysts at China Galaxy Securities said in report.

** The United States said on Wednesday it would now require senior Chinese diplomats to get State Department approval before visiting U.S. university campuses or holding cultural events with more than 50 people outside mission grounds.

** The recovery in China's service sector activity extended into a fourth straight month in August, an industry survey showed, with companies hiring more people for the first time since January.

** The services sector, which accounts for about 60% of the economy and half of urban jobs, had been slower to return to growth initially than large manufacturers, but the recovery has gathered pace in recent months as coronavirus curbs eased. (Reporting by Luoyan Liu and Brenda Goh; Editing by Shailesh Kuber)