Shanghai's composite index fell sharply at the opening on Wednesday, after having surged the day before in the wake of comprehensive Chinese stimulus packages. By lunchtime, it was down 4.9 percent, while Shenzhen's composite index had fallen by 6.5 percent.
Hong Kong's Hang Seng index had also lost 1.3 percent by lunchtime.
In Japan, there were mixed signals. The important Nikkei 225 was up 0.6 percent, while the broader Topix index was hovering around zero.
