SHANGHAI: The mainland's key index ended up 2.59 percent, partly led by China State Construction Engineering Corp on news that its parent was buying more shares in the listed unit, as institutional investors returned to the market after winding up year-end settlements.

The Shanghai Composite Index finished up 79.63 points at 3153.41, scoring its biggest daily percentage gain this month and regaining the key 125-day moving average, now at 3098.

The index was also boosted as prospects for China's economic recovery offset the negative impact of heavy new share supplies.