SHANGHAI, July 20 (Reuters) - Chinese stocks slipped on Thursday, erasing gains in early trade as the government's vow to support the private economy failed to excite investors, while Hong Kong shares were slightly up.

** China's blue-chip CSI 300 Index and the Shanghai Composite Index edged down 0.1% and 0.3%, respectively by the midday recess.

** Hong Kong's Hang Seng Index added 0.3% while the Hang Seng China Enterprises Index rose 0.4%.

** However, the Hang Seng Tech Index was down 0.3% by the midday, after rising as much as 1.5%.

** China on Wednesday pledged to make the private economy "bigger, better and stronger" with a series of policy measures designed to help private business and bolster the flagging post-pandemic recovery.

** "While the encouraging tone should be welcomed by private businesses, the supports may not be concrete enough to revive business confidence," UBS analysts said in a note.

** BofA became the latest bank to cut China's economic growth forecast for this year to 5.1% on a disappointing second-quarter GDP growth and potential delay in forceful policy response.

** The bank also said its latest Asia Fund Manager Survey shows that expectations for China lack hope, with a majority (57%) of investors bracing for new lows in China equities, undershooting the October-2022 lows.

** China left its lending benchmarks unchanged on Thursday, after the central bank stood pat on a key policy rate earlier this week even as signs of a faltering economic recovery called for more stimulus.

** Artificial intelligence stocks led onshore market's decline by slumping 2.9%.

** China property developers listed in Hong Kong rose more than 3% after Bloomberg News reported that Chinese authorities are weighing easing home buying restrictions in the country's biggest cities.

** All eyes are on an expected Politburo meeting later this month, when top leaders could chart the policy course for the rest of the year. (Reporting by Shanghai Newsroom; Editing by Varun H K)