Chinese shares closed mixed Wednesday as the key Shanghai stock index struggled but failed to break past 3,400 points.

The benchmark Shanghai Composite Index went up 0.16 percent to end at 3,388.28 points, and the Shenzhen Component Index closed 0.15 percent down at 11,312.5 points.

Total turnover on the two bourses stood at 568.5 billion yuan (about 86.4 billion U.S. dollars), up from 542.3 billion yuan on the previous trading day.

The IMF raised its forecast for China's economic growth in 2017 and 2018 Tuesday, citing the stronger than expected performance in the first half of the year and continuous policy support.

In its latest World Economic Outlook, the IMF expected the Chinese economy to grow 6.8 percent this year and 6.5 percent next year, 0.1 percentage point higher than its previous forecast in July.

Logistics and liquor producers led the gains Wednesday. Jiangsu Yanghe Brewery went up 4.96 percent to end at 108 yuan per share, while Wuliangye Yibin Co. Ltd. gained 3.38 percent to 61.18 yuan a share.

The ChiNext Index, which tracks China's NASDAQ-style board of growth enterprises, lost 0.83 percent to close at 1,901.55 points.