Shanghai shares opened down more than three percent on Monday, despite China authorising its state pension fund to invest in stocks, the authorities' latest attempt to shore up the markets.

The benchmark Shanghai Composite Index slumped 3.83 percent, or 134.26 points, to 3,373.48. The Shenzhen Composite Index, which tracks stocks on China's second exchange, dived 4.32 percent, or 88.12 points, to 1,951.28.