SHANGHAI: China shares fell on Friday on worries over tightening government regulations but were still set for their biggest weekly gain in six following a sharp drop last week.

** At the midday break, the Shanghai Composite index was down 0.48% at 3,449.85 points. That trimmed its gains for the week to 1.5%, its biggest since late June, after slumping 4.3% last week.

** China's blue-chip CSI300 index was down 0.73%, cutting its weekly gain to 2.1% - also the biggest since late June. The index fell 5.5% last week.

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** The healthcare sector was the biggest drag, falling 4.37% by midday. Information technology firms fell 1.31% and consumer staples lost 0.71%.

** Education firms also fell, with an index tracking the sector in mainland and Hong Kong markets falling 1.08%. The index, walloped by last month's banning of curriculum-based for-profit tutoring in China, is on track to post its eleventh straight weekly decline.

** Duolingo Inco said on Thursday it was aware that its popular language learning app was no longer available for download on some Chinese app stores, following the tutoring crackdown.

** Chinese H-shares listed in Hong Kong fell 0.14% to 9,283.62, but the benchmark Hang Seng Index eked out a gain, rising 0.01% to 26,206.75.

** Shares of highly indebted property developer China Evergrande Group slumped 3.85% after rating agency S&P Global downgraded the credit ratings of Evergrande and some subsidiaries.

** The smaller Shenzhen index was down 0.42%, the start-up board ChiNext Composite index was weaker by 1.16% and Shanghai's tech-focused STAR50 index was down 1.2%?.

** Around the region, MSCI's Asia ex-Japan stock index was weaker by 0.18%, while Japan's Nikkei index was up 0.32%.

** The yuan was quoted at 6.4643 per US dollar, 0.05% weaker than the previous close of 6.461.