SHANGHAI, June 21 (Reuters) - China stocks surrendered initial gains and closed lower on Tuesday, a reflection of weak investor sentiment amid worries about the economy.
The CSI300 index of the largest listed companies in Shanghai and Shenzhen fell 0.2 percent, to 3,106.32, while the Shanghai Composite Index lost 0.4 percent, to 2,878.56 points.
The indexes rose in the morning session, tracking global markets as expectations grew that British voters will opt to remain in the European Union in Thursday's referendum.
But the market suffered a bout of selling in the afternoon session, with small-caps leading the declines.
Shenzhen's start-up board ChiNext lost 1.4 percent. (Reporting by the Shanghai Newsroom; Editing by Richard Borsuk)