HONG KONG (AP) — China’s markets regulator on Friday renewed its efforts to pep up the stock market, pledging to raise the quality of companies listed on domestic markets.

The China Securities Regulatory Commission issued draft guidelines to more strictly vet applications for share listings and to more closely oversee listed companies by measures such as on-site inspections.

Regulators reiterated pledges to prevent and punish fraud and other illegal activities, saying there would be “zero tolerance” for illegal practices like falsifying information, insider trading and market manipulation.

Chinese markets have fallen to multi-year lows as the economy has slowed, and the property sector has languished after authorities cracked down on excessive borrowing by developers.

Chinese companies have lost billions of dollars worth of market value as investors shifted away from the markets in Hong Kong and the mainland in search of better returns elsewhere.