HONG KONG, Sept 17 (Reuters) - Hong Kong shares steadied at 4-1/2-month highs on Monday, with strength in Chinese oil giant CNOOC Ltd on higher oil prices offsetting weakness in Chinese property counters.
The Hang Seng Index closed up 0.1 percent at 20,658.1, the highest since early May. The China Enterprises Index of the top Chinese listings in Hong Kong ended down 0.5 percent at 9,780.9.
In the mainland, the CSI300 Index of the top Shanghai and Shenzhen listings shed 2.5 percent, its worst loss since June 4. The Shanghai Composite Index lost 2.1 percent, its worst loss since July 9.
* The Chinese property sector slid after mainland news reports that Beijing property sales in the first two weeks of September slipped more than 20 percent from a month earlier, suggesting curbs on the sector have hit sales during the traditional September-October peak season. China Overseas Land shed 1.8 percent, while China Resources Land slumped 3.4 percent also on reports that it could buy property from its parent company.
* Hong Kong Exchange (HKEx) rose in heavy volumes for a third-straight session, jumping 2.5 percent to its highest close since early May. Investors are betting that the third round of quantitative easing announced by the U.S. Federal Reserve last week could boost sagging trading volumes in the Chinese territory.
* Along with HKEx, CNOOC was among the top boosts to the Hang Seng Index, rising 3.7 percent as Brent crude rose for the eighth day to near $117 per barrel. (Reporting by Clement Tan; Editing by Anne Marie Roantree)