SHANGHAI, Oct 17 (Reuters) - Dozens of China-listed companies announced plans on late Monday to buy back shares or scrap plans of stock selling, following a slew of measures authorities took to boost a flagging stock market.

This follows more than a hundred Chinese companies committing to buybacks or withdrawing share sales in August after China imposed new rules as part of measures to shore up a sinking stock market as the country's post-COVID-19 recovery lost momentum.

Its blue-chip stock index, however, is near one-year lows as investor sentiment remained weak in recent months despite stimulus policies to shore up confidence.

More than a dozen Chinese companies, including China Petroleum & Chemical Corp, China Railway Construction Corp, China Mobile said in stock exchanges filings on late Monday that they had purchased back their shares or plan to buy back shares in public markets.

Meanwhile, more than 70 other companies in filings vowed that their major shareholders would not sell shares in the coming months, or withdrew plans to offload shares.

Wanma Technology and GoodWe Technologies Co both said in their own statements that their controlling shareholders would not sell stocks in the next six months, based on confidence in their companies' future development.

It comes as China's state fund Central Huijin Investment increased stakes in China's "Big Four" state banks last week, fuelling hopes that the authorities would step in to rescue the market. (Reporting by Jason Xue in Shanghai and Tom Westbrook in Singapore Editing by Marguerita Choy)