Shanghai shares surged more than five percent on Monday afternoon on speculation of a merger between two major state-owned shipping enterprises, despite weak economic figures released over the weekend, dealers said.

The benchmark Shanghai Composite Index was up 5.02 percent, or 187.84 points, to 3,932.04. The Shenzhen Composite Index, which tracks stocks on China's second exchange, gained 4.65 percent, or 101.25 points, to 2,278.40.