China's export and import performance in September easily beat forecasts, with imports showing unexpected buoyancy, helping to ease concerns about deteriorating domestic demand in the world's second-biggest economy.

Exports rose 15.3 percent in September from a year earlier, beating a median forecast in a Reuters poll for a rise of 11.8 percent.

Imports rose 7 percent in terms of value, compared to a Reuters estimate for a 2.7 percent fall.

"The big implication is that import (growth) is much stronger, so that no matter what is the reason, I think it will cool off a bit of the concern about domestic weakness bringing down economic activity," said Zhu Haibin, an economist at JPMorgan.

Nevertheless, Zhu said he expects policymakers to continue to unveil further modest measures to help shore up growth.

China's economy, the world's second largest, has had a bumpy ride this year. Activity has been dampened by unsteady exports and a slowdown in domestic demand that has been compounded by a cooling housing market, prompting a flurry of government stimulus measures.

The latest Reuters poll showed the economy likely grew at its weakest pace in more than five years in the third quarter as the property downturn weighed on demand, raising the chances of more aggressive policy steps that may include cutting interest rates.

However, the unexpectedly strong trade performance, if sustained, could temper any further policy action.

Chinese Premier Li Keqiang said late last week that China will avoid a hard landing despite worries over a slowdown in the world's number-two economy and a flagging real-estate market. He also said he was confident the economy would continue to grow at a "medium to high tempo", forecasting growth of about 7.5 percent this year despite turbulence in the world economy.

China posted a trade surplus of $31.0 billion in September, down from $49.8 billion in August.

Third quarter GDP along with September retail sales, industrial output and investment data will be released on Oct. 21.