China's exports and imports rebounded sharply in September, beating market expectations, customs data showed Monday, offering hope that the world's second-largest economy has arrested a further decline and is building momentum.

But the country is still facing pressure to meet its annual trade target and medium-to-high growth rates in foreign trade may become new norms, the General Administration of Customs (GAC) said.

Exports rose 15.3 percent year-on-year in September, expanding from a 9.4 percent increase in August, GAC data showed on Monday.

Imports grew 7 percent in September from a year earlier, following a 2.4 percent drop in August, the data showed.

The rebound in imports meant the trade surplus narrowed to $31 billion in September from $49.8 billion the previous month.

GAC spokesperson Zheng Yuesheng attributed the strong figures to the government's measures to support trade and rising external demand driven by the economic recovery of major economies as well as improved customs clearance efficiency.

  "The country's foreign trade has been improving quarterly. The good momentum in trade may continue in the fourth quarter, especially in exports, indicating the pressure on export growth will abate in the coming two or three months," Zheng said at a press briefing in Beijing. 

Exports expanded 12.8 percent year-on-year in terms of the yuan value in the third quarter, up from 3.4 percent growth in the second quarter and a 6.1 percent decline in the January-March period, Monday's data also showed.

Imports grew 0.9 percent in the third quarter, compared with the flat growth in the second quarter and a 1.2 percent drop in the first quarter, the data showed.  

Zhang Lei, a Beijing-based macroeconomic analyst with Minsheng Securities, told the Global Times on Monday the improved trade was aided by seasonal demand and stable currencies.

"The Western holidays are about to start and holiday demand will continue to remain high during the period from Halloween to Christmas, and the stable currencies have prompted exporters and importers to rush to close deals, pushing up orders and exports," Zhang said.

"The rising exports also drive the demand for imports as businesses need to import materials to manufacture goods and complete orders," said Wang Jun, an economist at the China Center for International Economic Exchanges (CCIEE), a Beijing-based think tank.

However, Zheng cautioned that China is still facing challenges in foreign trade as it is losing competitive advantages in terms of export products in labor intensive manufacturing industries to Southeast Asian countries, developed economies are cutting on investment in manufacturing in China, and prices of commodities continue to drop. 

"It is very difficult to meet the annual trade growth target of 7.5 percent this year … China's foreign trade is experiencing a change of gear and structural adjustment. The medium-to-high growth rates in trade have become the new norms," Zheng said. 

"The ongoing declines in ordinary imports, shipments from commodity producers and imports of some raw materials and commodities all still point to soft domestic demand," economists led by Wang Tao, chief China economist with UBS AG, said in a research note e-mailed to the Global Times on Monday.

"Looking forward, as the ongoing property downturn brings larger repercussions to other industries, domestic demand will face more headwinds down the road," said Wang Tao.

China's economy has experienced bumpy growth in the first two quarters of 2014, affected by sluggish property investment, which accounted for around 20 percent of the total fixed assets investment, unsteady trade and unimpressive retail sales.

"It seems that the impact of the slump in the property sector on the economy has been underestimated," Wang Jun said. "But it does not mean China has lost its international competitive edge or steam in economic growth. The benefits of China's ongoing reforms to the economy will be seen in the coming periods."  

Premier Li Keqiang, who has insisted on avoiding a major stimulus to focus on restructuring and reforms, emphasized Saturday at the Hamburg Summit in Germany that China's economy will avoid a hard landing and is capable of achieving around 7.5 percent growth in the year.