HONG KONG -- Investors are snapping up property near a proposed $45 billion business zone in the Chinese boom town of Shenzhen, betting that the government's plans to further open its capital markets with a "mini-Hong Kong" will spur real estate values.

Prices for some new residential projects near Qianhai, just an hour by car from Hong Kong, average around 33,800 yuan ($5,300) per square meter. That is nearly double the going rate in Shenzhen, a metropolis of 10 million crammed with ports and skyscrapers and home to Chinese corporate goliaths such as carmaker BYD Co and Huawei Technologies.

Growth in residential property prices in China's major cities has outpaced that of average household incomes by 16 times over the last two decades, according to a Credit Suisse report. Fears of a bubble led to a series of tightening measures to rein in prices, which fell in 21 cities in June versus 40 in May, according to official data.

"It's too early to decide whether it will become a bubble," said Raymond So, Dean of School of Business at Hang Seng Management College in Hong Kong, when asked if Qianhai would disappoint.

Detailed zoning plans are not yet in place, making it difficult to assess the real value of property in the Qianhai area, So said.

Qianhai, a 15-square-kilometer experimental zone for service sector reforms, had collected accumulated investment intentions worth 300 billion yuan as of July 16, said Shenzhen Party Secretary Wang Rong.

Investors have looked beyond the sparse and muddy reclaimed zone, snapping up unfinished properties, with a jump in sales clearly evident after China unveiled details of the project at a high-profile ceremony at the end of June.

In many ways, Qianhai resembles Shenzhen three decades ago before it became a pioneer of China's economic reforms. In 1980, the city was no more than a bucolic backwater of 30,000 villagers living off paddy fields and the sea.

Qianhai officials signed co-operation deals with 37 companies in Hong Kong this week, while Chinese private equity firm Hony Capital said it had been appointed to bring leading foreign funds to the zone, a sign that China is wasting no time in developing the area.

The flood of interest comes amid signs of a turn in China's property prices, which broke eight straight months of decline in June, signaling that pro-growth policies are gaining traction.

Commercial property stocks are also benefiting.

Shares of Shenzhen government-backed commercial property developer Shahe Industry, which is 15 minutes by car from the proposed business zone, hit their highest in more than a year in early July even though a company executive said it had not signed any deal on the Qianhai project. Its shares have surged more than 70 percent so far this year, outpacing an 18 percent gain in China's property index.

Some market watchers, however, are skeptical.

"The Qianhai concept and government tie may have played into the share price surge, but solely investing in the concept is irrational," said a Shenzhen-based analyst who declined to be named.

Rongjiang Tianyu, an apartment complex being developed by Shenzhen Rongjiang Industry Co Ltd, has less than 10 units left out of 156 that went on sale on July 4, said a property saleswoman surnamed Chen.

She said 90 percent of the units, which are due to be ready for tenants towards the end of 2013, were sold on the first day. The units are priced almost double the Shenzhen average of 19,000 yuan per square meter.

Dananshan Ziyuan, a block of town houses advertised online as "being right in greater Qianhai" and "having immeasurable future appreciation potential," has villas on sale for up to 100 million yuan, another saleswoman surnamed Li told Reuters.

Units went on sale in early June and about 10 of 91 villas are left, while one of two 100-million-yuan houses has been sold, Li said.

Some of the most expensive homes in the block cost 236,406 yuan ($37,100) per square meter, compared with the $27,200 per square meter for a luxury unit in Paris, or $23,300 per square meter in New York's Manhattan district in 2011, according to data from Knight Frank.