* SSEC -1.1 pct, CSI300 -1.0 pct, HSI -0.5 pct
* China's Q1 GDP growth seen at 6.8 pct - think tank
* China facing heightened financial risks from property downturn - Moody's
* Li & Fung Ltd tumbles as profit misses expectation
SHANGHAI, March 30 (Reuters) - China stocks were headed for a fourth day of losses on Thursday morning, with risk appetite soured by worries over property market prospects, sharp declines in newly-listed stocks, and liquidity stress as the month-end approaches.
The bearish sentiment spilled over to Hong Kong, where the market edged lower without the support of southbound inflows.
The CSI300 index fell 1.0 percent, to 3,430.67 points at the end of the morning session, while the Shanghai Composite Index lost 1.1 percent, to 3,205.00 points.
The tech-heavy start-up board slid 1.6 percent to a five-week low.
The National Academy of Economic Strategy, a government think tank, urged the authorities to guard against risks in the property and financial sectors by properly managing monetary and land supply "floodgates", the official Xinhua agency reported - adding to concerns about more restrictions on property developers.
Further hurting sentiment, Moody's Investors Service warned that the financial risks facing China from a potential property downturn had grown as record lending had made banks more risk-prone while the government was less able to combat those risks.
An index tracking real estate developers fell 1.3 percent at midday.
Zhang Qi, an analyst at Haitong Securities, said liquidity worries kept investors sidelined. China's central bank skipped open market operations for a fifth day and was set to drain 40 billion yuan ($5.80 billion) on Thursday.
Zhang noted that recent sharp losses in newly-listed stocks, usually overpriced because of speculation, also weighed on the market.
"It would be hard to maintain the high valuation if their growth in revenue fail to match the prices," he said.
Jiangsu Jiejie Microelectronics Co Ltd and Gansu Longshenrongfa Pharmaceutical Industry Co Ltd, both listed for less than a year, fell 10 percent by the lunch break, the maximum allowed.
In Hong Kong, the Hang Seng index dropped 0.5 percent, to 24,277.76 points, while the Hong Kong China Enterprises Index lost 1.0 percent, to 10,333.66 points.
Southbound trading between mainland cities and Hong Kong through connect schemes was suspended until April 5 for a holiday break.
Shares lost ground across the board in Hong Kong.
Li & Fung Ltd plummeted more than 9 percent after the firm reported a 47 percent slide in annual net profit, missing expectations. ($1 = 6.8945 Chinese yuan renminbi)
Reporting by Jackie Cai and John Ruwitch; Editing by Eric Meijer