* HSI -0.6 pct, H-shares -0.3 pct
* HSBC's Hong Kong shares fall 4 pct, at lowest since Sept 2012
* Casino stocks under pressure on profit-taking
* Hutchison, Cheung Kong, SHKP to report earnings this week
HONG KONG, Feb 24 (Reuters) - Hong Kong stocks fell on Tuesday, with HSBC Plc leading the slide after disappointed earnings, and casino stocks were under pressure as investors locked in gains while awaiting earnings reports from blue chips later this week.
The Hang Seng index, which has risen the past six sessions, slid 0.6 percent to 24,694.03 points by the lunch break. The China Enterprises Index of the top Chinese listings in Hong Kong was down 0.3 percent to 12,005.07 points.
Mainland China markets, which have been closed since Feb. 18 for the Lunar New Year holiday, reopen on Wednesday. Hong Kong reopened on Monday.
"Investors are cautiously bullish on the mainland markets and are anticipating a strong start as they reopen," said Alex Wong, a director at Ample Finance Group.
Hong Kong-listed shares of HSBC dropped 4 percent after the UK emerging markets-focused bank reported a deeper-than-expected 17 percent slide in annual pretax profit and cut its earnings target.
HSBC stocks fell to as low as HK$69.15, their weakest since September 2012, before recovering slightly to be down 3.3 percent for the day at HK$69.60. Shares of its Hong Kong subsidiary Hang Seng Bank were down 1.6 percent.
Conglomerate Hutchison Whampoa and property group Cheung Kong will report yearly earnings on Thursday. Sun Hung Kai Properties and New World Development are due to announce results on Friday.
Shares of casino operator remained weak as investors locked in gains. Galaxy Entertainment was down 2.5 percent and Sands China lost 2.4 percent. (Editing by Richard Borsuk)