Investor confidence was also hit by a fresh Moody's downgrade of Shimao's rating, highlighting the debt travails bedevilling some bloated developers, despite targeted policy easing by Beijing to prevent a hard-landing of the industry.

Shimao's Hong Kong-listed shares slumped more than 9% in morning trading to a one-month low.

A Shimao bond tumbled 22% in Shanghai, the biggest decliner in the city's exchange market for corporate bonds. Several other Shanghai-traded bonds issued by Shimao fell more than 6%.

Some 1.1 billion yuan ($174.11 million) of asset-back notes guaranteed by Shimao may not be redeemed when they mature next month, trustee Yunnan International Trust Co said in filing that was disclosed on Wednesday.

Also on Wednesday, global rating agency Moody's downgraded Shimao's corporate family rating (CFR) again, citing the firm's heightened liquidity risks over the next 6-12 months.

Moody's also changed Shimao's outlook to negative from ratings under review, as the developer faces large upcoming debt maturities.

China stepped up its deleveraging campaign last year against heavily indebted developers, driving the industry into a liquidity crisis that led to defaults by China Evergrande Group and a slew of smaller rivals.

Although China has taken a series of measures in recent months to revive confidence in a sector suffering from falling prices and slumping sales, there's no sign Beijing will reverse its deleveraging policies.

China's housing minister pledged on Thursday to keep the real estate market stable this year and ensure "genuine demand" for homes is met.

(Reporting by Samuel Shen and Andrew Galbraith; Editing by Shri Navaratnam)