* SSEC -0.3%, CSI300 0.0%, HSI -0.7%
* HK->Shanghai Connect daily quota used -4%, Shanghai->HK daily quota used 3.4%
* FTSE China A50 +0.1%
SHANGHAI, May 20 (Reuters) - Hong Kong stocks fell on Thursday, as energy and materials firms retreated after Beijing vowed to curb sky-high commodity prices by stabilizing the market.
** The Hang Seng index dropped 0.7% to 28,382.02 points, while the Hong Kong China Enterprises Index lost 0.4% to 10,613.27.
** The Hang Seng energy index and Hang Seng materials index slumped 4.5% and 4.7%, respectively, by midday.
** Yanzhou Coal Mining Co Ltd , Jiangxi Copper Co Ltd and Zijin Mining Group Co Ltd
shed between 4.2% and 8.4%.
** China will strengthen its management from both supply and demand sides to curb "unreasonable" increases in commodity prices, and prevent the pass-through to the consumer, the cabinet said on Wednesday.
** The comments drove prices of commodities including steel and iron ore to extend recent losses after surging this year on the back of post-lockdown recoveries in demand and easing liquidity globally.
** Digital currency and blockchain-related stocks also pulled back after a cryptocurrency slump.
** However, analysts saw a very limited impact on the broader market from the cryptocurrency fallout.
** Chinese investors' participation in cryptocurrencies is very limited due to Beijing's continued clampdown, said Yan Kaiwen, an analyst with China Fortune Securities.
** Yan said Bitcoin mining has consumed too much of China's resources, including coal, at a time when Beijing seeks carbon neutrality.
** Despite the weakness, mainland investors continued their buying, purchasing a net 4.5 billion yuan ($698.94 million) worth of Hong Kong shares on Thursday, according to Refinitiv data.
** Shares of China's e-commerce co JD.com Inc rose as much as 4.1% to HK$281.80, their highest since May 12 as first-quarter revenue topped estimates.
** On the mainland, the CSI300 index was unchanged at 5,174.50 points at the end of the morning session, while the Shanghai Composite Index lost 0.3% to 3,500.86 points.
** The CSI300 energy and the CSI A-share resource industries index dropped 2.6% and 3.1%, respectively.