Free trade door open, or is it just ajar?

It has been billed as a game-changing testing ground for much-needed reforms in the world's second-largest economy, and possibly the most significant act of opening up since China joined the World Trade Organisation more than a decade ago.

But for all the burning anticipation surrounding Shanghai's free-trade zone, the extent and timing of the toughest financial reforms remained uncertain, and possibly years away, even as the 28-square-kilometre zone was officially launched in an understated ceremony on Sunday.

A blueprint unveiled by China's State Council cabinet on Friday foreshadowed a range of ambitious reforms, from liberalising interest rates to full yuan convertibility in the pilot zone within the next three years.

"It will become a vehicle to more deeply integrate our country in globalisation and we will work hard to carry out the reform experiments over the next two to three years," the State Council said in a statement.

But the reforms have been outlined only in broad strokes, and hopes of more specific information to be released on Sunday did not materialise.

The driving force behind the free-trade zone has been Premier Li Keqiang, who has said the Shanghai model would be replicated across the country if it proves successful.

Officials in Shanghai have struck a cautious tone, underlining the resistance from the dominant state-owned sector, and the pressure on Shanghai to get things right.

"Some are concerned that the establishment of the Shanghai zone is like letting a wolf through the door. It might expose our uncompetitive industries," Chen Bo, the deputy director of the Shanghai Free Trade Research Centre said.

"There is the possibility that some interest groups, who have benefited from the current financial structure and regulations won't easily give up their vested interests.

"Our government is trying to push things forward, but we do have some [other] powers trying to draw it backward."

One Shanghai-based executive with a major state-owned bank told Fairfax Media that the whole process had appeared "rushed", and a mixture of poor co-operation and lack of enthusiasm from state-owned banks had meant the project lacked impetus.

"We're accustomed to clear instructions from the central government," he said. "But there is a lot of caution."

Nonetheless, excitement over the launch has boosted stocks of Shanghai companies and spurred a rally in the cost of houses and land in areas neighbouring the zone in recent weeks.

Restrictions on foreign investment will be eased inside the zone, which will also loosen controls on 18 service sectors ranging from finance and shipping to culture services.

China will allow foreign banks to skip long and often bureaucratic approval processes when setting up their wholly owned units in the free-trade zone. Pan Zhengyan, the deputy director of the Shanghai Academy of Social Sciences Financial Centre, said that despite years of financial reform talk China still had to be prudent.

"If the government acts too quickly on financial reform, I think we will see crimes like money-laundering flourish in the zone," he said.

"The government might be wary of such problems but criminals often act a few steps ahead."

State media have touted the Shanghai zone as the most important attempt at economic reform since the creation of the country's first special economic zone in 1980 in Shenzhen, which harnessed cheap labour and helped transform China's manufacturing industry.

But an economist with Bank of America Merrill Lynch, Lu Ting, said such comparisons could prove overstated.

"My overall impression is that it's good but people should avoid being overly excited," he said.