Share prices closed the morning lower, pressured by Wall Street's overnight weakness following weak US retail sales data, dealers said.
Caution ahead of the announcement of details of the Tracker Fund's third quarter unit sales also contributed to the selling pressure, they said.
The Hang Seng index closed the morning down 100.72 points or 0.98% at 11,018.61, off a high of 11,066.75 and a low of 10,994.54, on turnover of 3.498 billion hkd.
The Hang Seng June contract was at 11,016 points.
The China Enterprises index was down 25.98 at 2,233.85, and the CAC index down 8.21 points at 1,249.23.
The GEM index was down 2.64 points at 195.93 on turnover of 98.618 million hkd.
The Tracker Fund was down 0.15 hkd at 11.10 hkd.
"The weakness on Wall Street was an important concern. Over the past quarters, the US economy was led by good consumption; now with the weaker data, sentiment will certainly turn cautious," Kenny Tang, associate director of research at Tung Tai Securities, said.
Tang said that concerns related to the Tracker Fund sales also weighed on the market.
"Market talk suggests that the likelihood of sales exceeding 6 billion hkd in the third quarter is high, which means the sales amount may be larger than before," he said.
The market may be concerned that the fund sales could lead to an increase in hedging and arbitrage activities, which will put pressure on stocks, he said.
The government is scheduled to announce details of the third quarter Tracker Fund unit sales after the market closes this afternoon.
Cheung Kong was down 0.75 hkd at 69.75, Henderson Land was flat at 33.20, while New World Development fell 0.05 to 6.50.
Sun Hung Kai Properties lost 0.75 at 60.50 after it rejected a report of a plan to issue 1 billion hkd worth of retail bonds.
Tang said sentiment towards the property sector is getting increasingly cautious ahead of a land auction on Monday. This will be the first land auction after the government announced the sales details for residential flats under the Home Ownership Scheme for the twelve months starting July.
Wheelock was unchanged at 6.75 ahead of its full-year results.
Hutchison Whampoa Ltd fell 0.25 to 64.00 amid reports that its unit Hutchison Port Holdings is looking at developing and managing a container handling facility at the port of Qingdao.
PCCW was down 0.01 at 1.90, China Unicom fell 0.05 to 7.05 and China Mobile dropped 0.20 to 23.85.
In the banking sector, Bank of East Asia fell 0.30 to 16.30, Hang Seng Bank dropped 0.75 to 84.75 and HSBC lost 1.25 to 91.25.
Among the red chips, China Resources Logic was up 0.02 at 0.90, Legend flat at 3.20, CNOOC steady at 3.20 and Denway Motors down 0.075 at 2.175.
Among H-shares , China Southern Airlines was down 0.025 at 3.225, Petrochina lost 0.02 to 1.72, Jiangsu Express was flat at 2.15 and Travelsky flat at 5.90.
tom.com fell 0.075 to 3.675 after it recorded a negative net tangible asset value of 238 million hkd as of end-March, following a series of acquisitions.
Hikari Tsushin, to be renamed China City Natural Gas, was down 0.022 at 0.184 after it settled a disagreement over the stakes in a gas joint venture with the China Gas Bureau.
i-Cable fell 0.05 to 5.50 after the Broadcasting Authority has cleared i-Cable Communications Ltd of predatory pricing against new industry entrants.
Wang on Group Ltd was down 0.002 at 0.016 and Dailywin was down 0.009 at 0.105 after Wang On said it will place 4.5 billion Dailywin Group Ltd shares at 0.01 hkd each in order to restore Dailywin's minimum public float requirement of 25%, dealers said.
Shenyang Public Utility Holdings fell 0.19 to 1.41 after the company sold its water business.
Sincere was down 0.04 at 0.33 following its full-year results.