By Summer Zhen

SHANGHAI, Sept 10 (Reuters) -

China stocks fell on Tuesday and were on track to a fresh seven-month low, as strong export data failed to allay market concerns about trade disputes and domestic deflation.

Hong Kong shares gained, thanks to the jump in Alibaba's Hong Kong shares as it was added to the Stock Connect Scheme, allowing mainland investors to buy the stock.

China's exports grew at their fastest pace since March 2023 in August, while imports missed forecasts amid weak domestic demand.

Analysts warn mounting trade barriers are emerging as another major obstacle despite strong August exports. "The question is how long exports can stay strong given the weakening U.S. economy and the rising trade tension," said Zhang Zhiwei, chief economist at Pinpoint Asset Management.

Shares of biotech firm WuXi AppTec Co Ltd dropped 8.3% in Hong Kong and 4.7% in mainland after the U.S. House of Representatives on Monday passed a bill that aims to restrict business with several Chinese biotech companies including Wuxi Apptec on national security grounds.

At the midday break, the Shanghai Composite index was down 0.53% at 2,722.01 points.

** China's blue-chip CSI300 index was down 0.52%, with its financial sector sub-index 0.15% lower, the consumer staples sector down 0.03%, the real estate index down 2.63% and the healthcare sub-index

down 1.34%. ** Chinese H-shares listed in Hong Kong rose 0.39% to 6,026.18, while the Hang Seng Index was up 0.28% at 17,244.67. ** The top gainers among H-shares were Alibaba Group Holding Ltd

, up 4.73%, followed by Li Auto Inc , gaining 3.76% and New Oriental Education & Technology Group Inc

, rising 2.69%.

** The smaller Shenzhen index was down 1.04%, the start-up board ChiNext Composite index was weaker by 0.88% and Shanghai's tech-focused STAR50 index was down 0.8%​.

** Around the region, MSCI's Asia ex-Japan stock index

was weaker by 0.03% while Japan's Nikkei index

was up 0.16%.

** The yuan was quoted at 7.118 per U.S. dollar, 0.05% weaker than the previous close of 7.1142.

(Reporting by Summer Zhen; Editing by Eileen Soreng)

((summer.zhen@thomsonreuters.com; 852-3462-7739;))