* SSEC -0.4%, CSI300 -1.1%, HSI -1.1%

* Energy firms gain as oil prices rise above $110

* Biden bans Russian flights using American airspace

SHANGHAI, March 2 (Reuters) - China shares fell on Wednesday with new-energy vehicle makers leading losses as investors dumped equities with high valuations amid worries over the impact of aggressive sanctions imposed against Russia. ** At the midday break, the Shanghai Composite index was down 0.41% at 3,474.45 points and China's blue-chip CSI300 index fell 1.05%.

** Leading the losses, the new-energy vehicle sector sub-index lost 2.11% and the CSI300 Industry fell 1.73%.

** The start-up board ChiNext Composite index slumped 2%, dragged lower by battery manufacturing heavyweight CATL , which lost 4.27%.

** The smaller Shenzhen index was down 0.84% and Shanghai's tech-focused STAR50 index slumped 1.09%.

** Chinese H-shares listed in Hong Kong fell 0.87% to 7,983.35 and the Hang Seng Index was down 1.07% at 22,518.18.

** Oil refiners bucked the sombre mood with the CSI Energy gaining 1.3% after oil prices surged past $110 per barrel. The sub-index of the Hang Seng Index, which tracks energy shares, rose 2.4%.

** U.S. President Joe Biden banned Russian flights using American airspace during his State of the Union speech on Tuesday, in which he also said Russian President Vladimir Putin would "pay a continuing high price over the long run" for the invasion of Ukraine.

** Hong Kong-listed shares of Russian aluminium producer OK Rusal plunged nearly 30% on Wednesday, hitting the lowest since November 2020 after miner and trader Glencore said it is reviewing all its business activities in Russia, including equity stakes in aluminium.

** Property shares and financial firms led losses in Hong Kong with the financial sector sub-index falling 2.04% while the property sector lost 1.21%. ** Around the region, MSCI's Asia ex-Japan stock index was weaker by 0.52% while Japan's Nikkei index was down 1.83%. ** The yuan was quoted at 6.3127 per U.S. dollar, 0.02% weaker than the previous close of 6.3113.

(Reporting by Shanghai Newsroom; Editing by Sherry Jacob-Phillips)