China's main stock index remained almost unchanged on Wednesday, due to weak performance of blue chips.

The Shanghai Composite Index closed at 3,612.40 points, 0.01 percent higher than the previous day.

A total of 594 companies in Shanghai A-share market gained, while 170 companies saw losses. Turnover at the market was heavy at 167.42 billion yuan.

Blue chips such as Sinopec, China Unicom, Industrial and Commercial Bank of China, Bank of China and Ping An all saw losses.

Analysts believe the market is vulnerable as more people may book profits after sharp gains this month.

(For more biz stories, please visit Industry Updates)