SHANGHAI, Feb 22 (Reuters) - Chinese stocks rose on Thursday, led by artificial intelligence (AI) shares after U.S. chipmaker Nvidia's better-than-expected revenue forecast. Hong Kong shares were roughly flat.

** China's blue-chip CSI 300 Index was up 0.3% by the lunch break, while the Shanghai Composite Index gained 0.5%.

** Hong Kong benchmark Hang Seng Index edged up 0.2%.

** China's AI stocks surged nearly 4% before entering the midday break up around 2.4%, after Nvidia on Wednesday forecast a roughly threefold surge in quarterly revenue, beating expectations.

** Cambricon Technologies, one of China's top AI-related chipmakers, jumped more than 10%.

** Coal and energy shares also rose, with PetroChina up 3%.

** Morgan Stanley equity strategists said in a note that the state-owned enterprises reform theme recently gained investors' attention as top-down policy focus seems to have returned.

** China Traditional Chinese Medicine Holdings surged more than 20% after a consortium led by state-owned pharmaceutical giant Sinopharm has revived a take-private bid for the company.

** Despite stock market performance improving on a raft of market rescue measures, investor sentiment can still be fragile without a material pickup in economic activities.

** "Offshore investors in general remain cautious. They believe the recent rebound is mainly driven by short-covering and bearishness ahead of the Lunar New Year," said analysts at UBS, adding that the property downturn and deflation remain major concerns.

** Meanwhile, Chinese hedge fund managers are scrambling to soothe investors after a rout in small-value stocks, even as regulators step up scrutiny of major market players' activities as they try to revive the country's ailing stock markets. (Reporting by Shanghai Newsroom; Editing by Varun H K)