The announcements by the companies, including China State Construction Engineering Corp and Aluminum Corp of China, came just days after 10 other central state-owned enterprises unveiled similar share purchase plans.
China's bluechip CSI300 Index slumped more than 2 per cent on Thursday to 11-month lows amid heavy foreign selling, even after Wednesday's release of better-than-expected economic data. "We see Beijing's measures to boost equity market sentiment having limited impact ... as investors are more focused on improvements in the real economy and company earnings before making a decisive longer term allocation to Chinese equities," said Gary Tan, portfolio manager at Allspring Global Investments.