HONG KONG, Sept 11 (Reuters) - Hong Kong's benchmark index ended lower for a fifth straight day on Thursday, failing to hold onto slim midday gains after China indexes slid into the red with investors turning cautious ahead of more economic data.
Also weighing on Asian market sentiment was U.S. President Barack Obama's speech vowing to fight Islamic State militants, which increased risk aversion.
The Hang Seng Index was off 0.2 percent at 24,662.64 points, a one-month closing low. The China Enterprises Index of the leading offshore Chinese listings in Hong Kong lost 0.8 percent.
Top percentage loser on the Hang Seng was Lenovo Group , which sank 4.2 percent after its chairman and CEO Yang Yuanqing cut holdings in the company.
Profit-taking continued to hurt major energy names. PetroChina shed 1.6 percent, CNOOC 1.2 percent, and Sinopec Corp 1.4 percent. (Reporting by Grace Li; Editing by Richard Borsuk)