SHANGHAI, April 19 (Reuters) - China's blue chips fell on Tuesday, while the Shanghai Composite Index gained, after the authorities vowed to support the economy hit by the country's worst domestic COVID-19 outbreak in two years.

The CSI300 index fell 0.4% to 4,150.28 by the end of the morning session, while the Shanghai index gained 0.1% to 3,199.30.

The Hang Seng index dropped 1.9% to 21,111.61. The Hong Kong China Enterprises Index lost 2.4% to 7,208.93.

** China will step up financial support for industries, firms and people affected by COVID-19 outbreaks, the central bank said on Monday.

** This came after data showed the economy slowed in March as consumption, real estate and exports were hit hard.

** "But the real growth bottlenecks remain," Nomura said in a note. "Adjustments to China's zero-COVID strategy are key to a growth recovery in coming months."

** By mid-April, the PBOC had paid 600 billion yuan ($94.31 billion) in profits to the central government - equivalent to a 25-basis points cut in banks' reserve requirement ratios (RRR), the central bank said.

** Healthcare firms and semiconductors went down 2% and 2.5%, respectively, while energy stocks gained 2.4%.

** China's state planner called for the implementation of policies to support the country's catering and retail sectors, spending on new energy vehicles.

** Consumer staples edged up 0.3%, while new energy vehicles were flat.

** Hong Kong-listed tech giants, down 2.8%, led declines on the Hang Seng index, as trading resumed after a holiday.

** Video and livestreaming platform Bilibili Inc slumped roughly 10%, after China banned livestreaming of unauthorized video games on Friday.

** Food delivery giant Meituan plunged 4.7% after Shanghai's market regulator said on Monday it had summoned 12 e-commerce platforms including Meituan and eleme.me over topics including price gouging during the pandemic.

(Reporting by Shanghai Newsroom; Editing by Rashmi Aich)