* SSEC -0.75%, CSI300 -1.34%, HSI -1.43% * Factory activity growth slows, services contract in August * Tech shares sink after Beijing tightens gaming rules * Ping An Insurance slumps as Reuters reveals new probe SHANGHAI, Aug 31 (Reuters) - China shares fell on Tuesday after data showed services sector activity contracted in August and as Beijing tightened rules around online gaming, but expectations of more economic policy support kept losses in check. ** At the midday break, the Shanghai Composite index was down 0.75% at 3,501.54 and the smaller Shenzhen index was down 1.37%. ** China’s blue-chip CSI300 index was down 1.34%, with its financial sector sub-index lower by 0.64%, the consumer staples sector down 1.54% and the healthcare sub-index down 2.28%. ** China’s businesses and the broader economy came under increasing pressure in August as factory activity expanded at a slower pace while the services sector slumped into contraction, raising the likelihood of more policy support to boost growth. ** “It seems the government is still aiming the end of this year to launch fiscal stimulus. This means growth will likely slow further in the coming months,” said Zhiwei Zhang, chief economist at Pinpoint Asset Management. ** High-tech firms sank, with a CSI information technology sub-index slumping 2.67%, after China introduced new rules forbidding under-18s from playing video games for more than three hours a week. ** The ChiNext Composite start-up board was 2.51% weaker and Shanghai’s tech-focused STAR50 index fell 2.8%. ** Chinese H-shares listed in Hong Kong fell 1.31% to 8,877.93, while the Hang Seng Index was down 1.43% at 25,174.17. ** Hang Seng heavyweight Tencent Holdings Ltd slipped 3.18% following the new rules on gaming. The Hang Seng Tech index fell 0.86%. ** Regulatory probes also weighed on Ping An Insurance Group Co of China Ltd, which fell 7.32% by midday after Reuters reported that China’s banking and insurance regulator was probing the company’s property market investments following a big profit hit from a soured bet. ** Ping An’s A-shares fell 3.45%. ** The yuan was quoted at 6.4678 per U.S. dollar. Reporting by Andrew Galbraith; Editing by Subhranshu Sahu Our Standards: The Thomson Reuters Trust Principles.