* HSI -0.1 pct, H-shares -0.7 pct, CSI300 -0.4 pct
* Chinese port-related shares up on plan for Yangtze River area
* Property shares decline in mainland, Hong Kong
(Updates to midday)
HONG KONG, June 12 (Reuters) - Hong Kong slipped on Thursday, joining other Asian markets after Wall Street stepped back from record levels.
China shares edged down as optimism brought by Beijing's mini-stimulus measures faded, though port shares outperformed after the State Council detailed a plan to develop an economic zone along the country's longest waterway.
At midday, the Hang Seng Index had inched down 0.1 percent to 23,226.21 points. The China Enterprises Index of the top Chinese listings in Hong Kong shed 0.7 percent.
The CSI300 of the leading Shanghai and Shenzhen A-share listings fell 0.4 percent, while the Shanghai Composite Index slipped 0.2 percent at 2,050.27 points.
"Sector rotation is driving the Hong Kong market. People are reshuffling their portfolios, probably because of the quarter-end approaching," said Alex Wong, director of asset management at Ample Finance Group.
Hong Kong developers, recent outperformers which fell on Wednesday, were weak again in the morning. Hang Lung Properties lost 1.3 percent and bigger rival Cheung Kong Holdings was off 1.0 percent.
In China, property sector was the biggest drag, with China Vanke and Poly Real Estate Group down 2.1 and 2.5 percent, respectively.
Shares of port groups soared after Beijing unveiled plans to develop the Yangtze river region, with Ningbo Marine surged by 10 percent, the maximum allowed, to a 7-week high. Ningbo Port gained 3.1 percent and Shanghai International Port Group 1.5 percent.
Chinese Premier Li Keqiang said on Wednesday the government should develop a comprehensive transport network in order to create an "economic belt" along the Yangtze river, according to the government's official website. (http://link.reuters.com/peq99v)
Shares of Weiqiao Textile fell 7.1 percent to their lowest in 16 months after the cotton yarn and fabric producer warned of a significant profit drop profit for the half-year ending in June as the Chinese government's cancellation of its national cotton temporary reserve policy hit sales and textile products prices.
Inner Mongolia Yili Industrial Group, the biggest CSI300 boost, rose 1.7 percent after one of its brands secured the title sponsorship for a popular TV show in the mainland, local media said.
(Additional reporting by Donny Kwok; Editing by Richard Borsuk)