* Guangdong shares rise on Pearl River Delta FTZ plans
* China property gain on comments from former official
* Summit Ascent Holdings jump on casino project stake
By Natalie Thomas
BEIJING, April 24 (Reuters) - China shares were mixed on Thursday as free trade zone development plans dominated trading, while Hong Kong stocks found support from earnings and a rebound in China Unicom.
The CSI300 index of the largest Shanghai and Shenzhen A-share listings edged up 0.1 percent by midday, while the Shanghai Composite Index was down 0.1 percent at 2,064.56 points.
The Hang Seng Index was up 0.1 percent at 22,533.20 points. The China Enterprises Index of the top Chinese listings in Hong Kong gained 0.3 percent.
Shanghai free trade zone firms continued to pull back after strong gains earlier in the week. Shanghai Waigaoqiao Free Trade Zone Development Co Ltd fell 2.3 percent and Shanghai Lujiazui Finance and Trade Zone Development Co Ltd dropped 4.1 percent by the lunch break.
But stocks with an exposure to the Pearl River Delta got an extra boost after the Guangdong provincial government said it would speed up the development of a free trade zone in the region, which would link Guangdong with Macau and Hong Kong.
Gemdale Corp shares jumped 10 percent, the daily trading maximum, while Huafa Industrial Co Ltd Zhuhai shares were up 5.2 percent. Shenzhen Yan Tian Port Holdings Co Ltd gained 3.7 percent.
Property stocks also gained after Chinese media reported a former official saying that the government would act cautiously to try and deflate the country's property bubble and that house purchase restrictions may soon be relaxed.
The CSI real estate sub-index jumped 2.15 percent on the news, with Poly Real Estate Group Co Ltd gaining 2.7 percent and Beijing Homyear Real Estate Co Ltd up 2.6 percent.
In Hong Kong, China Unicom Hong Kong Ltd was the biggest gainer on the Hang Seng, rising 2.8 percent after investors bought back the stock following a sell-off on Wednesday when its main competitor China Mobile Ltd posted its worst quarterly results in 5 years.
"Yesterday's reaction was too drastic," said Alex Wong, director of asset management at Ample Finance Group.
"Unicom in the short term should do better than China Mobile because China Mobile needs to dump a lot of money on expanding its infrastructure."
Shares of GOME Electrical Appliances rose as much as 6.3 percent during morning trade, hitting their highest since April 2012 after the Chinese home appliance retailer said it expected to see a sharp rise in its first quarter profit.
Summit Ascent Holdings Ltd topped the most actively traded stocks, surging 12.3 percent after the firm said it would raise its stake in a casino resort project in Russia by 14 percent for $20.2 million, a deal to be funded by proceeds from a share sale. (Additional reporting by Donny Kwok; Editing by Jacqueline Wong)