* HSI -0.3 pct, H-shares -0.7 pct, CSI300 -1.5 pct
* China property sinks after Beijing tightens pre-sales requirement
* Jiangxi Copper drops, also hurt by Macquarie downgrade
* StanChart rebounds from more than 5-month closing low
By Clement Tan
HONG KONG, May 14 (Reuters) - Mainland China shares suffered their worst daily loss in three weeks on Tuesday, forcing a reversal of early gains in Hong Kong markets, after official media suggested that Beijing is unlikely to ease monetary policy despite patchy April economic data.
The Chinese property sector was also hit by fears of more tightening after the 21st Century Business Herald reported that pre-sales rights for new housing projects in Beijing now require the added approval from the mayor's office.
The CSI300 of the leading Shanghai and Shenzhen A-share listings shed 1.5 percent. The Shanghai Composite Index slid 1.1 percent. Both indexes suffered their worst loss since April 23.
The Hang Seng Index slipped 0.3 percent, while the China Enterprises Index of the top Chinese listings in Hong Kong declined 0.7 percent, each slipping further from last Friday's two-month closing highs.
Losses in Hong Kong came in the weakest turnover since May 6, just over 5 percent below its average in the last month. Shanghai volume sank to its lowest since May 2.
"The latest set of data suggests the economy remains sluggish, and with policy easing looking unlikely, we might be see more weakness when investors sell off the small and mid-cap names, which have been outperforming on the year," said Zhang Qi, a Shanghai-based analyst with Haitong Securities.
On Tuesday, the CSI500 of small- and mid-cap names listed in the mainland fell 1.2 percent, but is still up more than 8 percent on the year. The CSI300 is down 1.2 percent, while the Shanghai Composite is down 2.3 percent in 2013.
Factory output growth and fixed-asset investment in the world's second-largest economy were weaker than expected last month, but the China Securities Journal reported that Beijing could tolerate 7 percent growth, compared to the current 8 percent annual target.
In the same article, Zhu Baoliang, the director of the State Information Center's economic forecasting department, said it is not possible for China to cut interest rates because monetary policy remains loose globally.
Beijing will complete April's batch of economic data with the release of figures for monthly direct foreign investment on Thursday and monthly home price data on Saturday.
Commodities counters were among the biggest percentage losers. Jiangxi Copper fell 2.1 percent, its third-straight loss in Hong Kong. Its Shanghai listing shed 2 percent.
Macquarie analysts downgraded their view on its H-share listing from "outperform" to "neutral", while cutting their price target by 32 percent, expecting copper prices to remain weak through 2014 due to a worsened surplus of supply.
Chinese property-related counters were also further hurt by a report in the Securities Times that new home prices were flat in the first 12 days of May, while volumes and prices in the secondary market declined in the capital.
China Vanke fell 2.7 percent in Shenzhen, while Poly Real Estate slid 3 percent in Shanghai. In Hong Kong, China Resources Land tumbled 3 percent, while China Overseas Land fell 1.5 percent.
Producers of Chinese premium alcohol, often offered as gifts to officials by those seeking favour, were hurt after Premier Li Keqiang called for less political power in China's market economy.
Kweichow Moutai dived 3.3 percent in Shanghai after closing on Monday at its highest since Jan. 23. Wuliangye shed 2.3 percent in Shenzhen and was set for its worst loss since March 27.
Standard Chartered rebounded 2.4 percent from Monday's more than five-month closing low. U.S. activist investors Muddy Waters told a conference last week it had bet against the bank because of its "deteriorating" loan quality.