Hong Kong shares fall 0.9 pct, led by CCB and HKEx

* CCB slips on stake sale by undisclosed seller

* HKEx tumbles further ahead of results

* HSBC provides market support after Q1 results (Updates to midday)

By Nerilyn Tenorio

HONG KONG, May 12 (Reuters) - Hong Kong shares were down less than 1 percent at midday on Tuesday after the benchmark index moved in a tight range, with sentiment still supported by a high level of liquidity and a firm mainland Chinese market.

Leading the fall was Hong Kong Exchanges and Clearing Ltd (0388.HK) ahead of its first-quarter results on Wednesday, while China High Speed Transmission (0658.HK) and China Construction Bank <0939.HK) were both hit by stake sales.

Hong Kong-listed companies from China did not benefit as much as their mainland counterparts from positive signs in the property sector and increased spending on renewable energy.

But some of the market's losses were offset by gains in HSBC (0005.HK) on optimism about the lender's prospects.

"The global economic outlook and corporate earnings have really been improving, and the market is more confident now about the outlook for the second half, but shares had over-reflected those positive signs," said Jaseper Tsang, head of research at CSC (Hong Kong), a unit of the Capital Securities Group.

The benchmark Hang Seng Index .HSI at midday stood 0.87 percent lower at 16,939.07, after Monday's trading snapped a seven-day rally.

The China Enterprises Index of top mainland companies was down 1.94 percent at 9,574.64.

China Shenhua (1088.HK) tumbled 6.4 percent to HK$22.75, while on the mainland, the Shanghai Composite Index .SSEC ended the morning 0.18 percent firmer, with property, coal and steel shares strong.

STAKE SALES

China Construction Bank (601939.SS) (0939.HK) fell nearly 2 percent to HK$4.81 after sources said an undisclosed, non-affiliated seller was disposing of $1.2 billion worth of shares in the Chinese lender. The sale was for 2.2 billion shares at HK$4.20 each, the sources said.

China High Speed Transmission (0658.HK) plunged 10.2 percent to HK$13.40 after the firm said its largest shareholder Fortune Apex Ltd would dispose of 65 million shares or a 5.22 percent stake in the company, reducing its holding to 21.56 percent.

The announcement did not mention a price for the stake sale. here