HONG KONG, Aug 23 (Reuters) - China stocks fell on Wednesday as investors stayed cautious amid a deepening crisis in the country's real estate sector and as a raft of share buybacks did little to boost confidence.

Hong Kong stocks gained, helped by earnings surprises by some internet and consumer companies.

** China's blue-chip CSI 300 Index dropped 0.72%, while the Shanghai Composite Index fell 0.55%.

** Hong Kong's Hang Seng Index rose 0.35%, and the Hang Seng China Enterprises Index climbed 0.36%.

** A growing number of Chinese listed companies and asset managers have announced plans to repurchase their own shares or fund products following calls from regulators to revitalise the stock market and boost investor confidence.

** A-share listed companies including Shanghai United Imaging Healthcare Co Ltd and Xinjiang Daqo New Energy Co were among the latest to announce share buyback plans.

** Local media estimated that more than 100 A-share listed companies have announced share buyback plans in the past week.

** Yet, market reaction is tepid as investors await bigger stimulus to address economic problems.

** Northbound trading in mainland shares via stock connect saw outflows for a 12th straight session on Tuesday.

** Property downturn means Chinese interest rates and the currency remain tilted to the downside unless a much firmer fiscal response is implemented, Goldman Sachs analysts said in a note, adding corporates face risks of further broad earnings downgrades.

** In Hong Kong, Anta Sports surged 12% after first-half net profit jumped 32% year-on-year.

** Baidu Inc rose 4.4% after the internet giant posted second-quarter revenue above estimates, helped by a post-pandemic recovery in advertising spending, and said it would further intensify its efforts on generative artificial intelligence.

** The Hang Seng Tech Index was flat. (Reporting by Summer Zhen; Editing by Subhranshu Sahu)