* HSI -1.6 pct, H-shares -1.7 pct, CSI300 -0.5 pct
* HK students undaunted by authorities' rejection of talks
* Mainland market in correction mode ahead of economic data
By Chen Yixin and Kazunori Takada
SHANGHAI, Oct 10 (Reuters) - Hong Kong shares slid on Friday afternoon, heading for their biggest percentage decline in two weeks on weakness in overseas markets and jitters over a possible flare up in pro-democracy protests in the city.
China's shares fell, pulling back from 20-month peaks hit the previous day, with analysts attributing the drop to investors consolidating positions after recent gains.
By midday, the Hang Seng Index dropped 1.6 percent to 23,147.81 points. If sustained, the drop would be the biggest percentage fall in two weeks. The China Enterprises Index of the top Chinese listings in Hong Kong fell 1.7 percent.
For the week, the HSI is still up 0.4 percent but the China index is down 0.4 percent.
"The Hong Kong stock market is just following the sharp decline on Wall Street," said Ben Kwong, head of research and director of KGI Asia in Hong Kong.
He added that some investors were getting nervous that the pro-democracy protests in Hong Kong could re-ignite after Hong Kong student protesters said they would maintain their campaign after the city government cancelled talks.
Wall Street on Thursday posted its largest percentage decline in six months on concerns about the strength of the global economy and its effect on corporate earnings.
The financial sector fell, erasing gains from Thursday, with Industrial and Commercial Bank of China sliding 1.2 percent, China Construction Bank slipping 1.3 percent, and HSBC Holdings sinking 1.6 percent.
On the mainland, the Shanghai Composite Index fell 0.6 percent to 2,375.28 points at the midday break while the CSI300 of the leading Shanghai and Shenzhen A-share listings dropped 0.5 percent.
For the week, the indices are up 0.5 percent and 0.7 percent respectively.
Liu Jingde, analyst at Cinda Securities in Beijing, said the Shanghai index was facing resistance as it approached the psychologically important 2,400 level.
Insurance shares fell, with Ping An Insurance (Group) Company of China and China Life Insurance Company Limited both slipping more than 1 percent.
Some analysts also said investors had turned cautious ahead of major economic data for September, including trade and inflation figures, due next week.
A Reuters poll showed that softer domestic demand probably pulled down growth in imports, investment and retail sales to multi-month or multi-year lows in September. (Additional reporting by Shanghai Newroom; Editing by Jacqueline Wong)