BEIJING (AFP) - China's trade surplus surged in May, official data showed on Sunday, as export growth accelerated sharply while imports showed a surprise fall.

Exports increased 7 percent to US$195.47 billion (S$244.7 billion) year-on-year, the General Administration of Customs announced, while imports declined 1.6 percent to US$159.55 billion, resulting in a surplus of US$35.92 billion (S$45 billion) - a 74.9 percent jump from the same month last year.

The result, China's third straight monthly surplus, surpassed the median forecast of a surplus of US$23.4 billion in a survey of 15 economists by Dow Jones.

Exports, which sharply outpaced April's 0.9 percent gain, were in line with the median prediction of a 7.2 percent rise, while imports missed their forecast of a 6.0 percent increase.

The mixed trade results came as worries over China's growth outlook have increased this year after a series of generally weaker-than-expected statistics, though trade data distortions have partially clouded the situation.

China's gross domestic product (GDP) grew 7.4 percent in the first three months of 2014, weaker than the 7.7 percent in October-December last year and the worst since a similar 7.4 percent expansion in the third quarter of 2012.

The country's trade statistics this year have been erratic, with Beijing reporting an unexpected trade deficit of almost $23 billion in February, which authorities blamed on the Lunar New Year holiday season. That was China's first monthly deficit in 11 months.

In March, China's trade volumes fell dramatically in a development that analysts blamed on the continued impact of fake over-reporting of exports seen in early 2013.

In a sign of optimism for China's economy, the country's manufacturing sector has shown renewed vigour recently, with key surveys indicating an improving situation.

The National Bureau of Statistics announced a week ago that the official purchasing managers' index (PMI) rose to 50.8 in May from 50.4 in April, the third straight month of improvement and a five-month high.

And, on Tuesday, British banking giant HSBC released a private PMI survey that showed it came in at 49.4, the highest reading since January's 49.5.

Both indexes are closely watched indicators of the health of the economy. A reading above 50 indicates expansion.

China's leaders say they want to transform the country's growth model to one whereby consumer spending and other forms of private demand become the key driver for the economy, rather than over-reliance on huge and often wasteful investment projects that have girded decades of expansion.

Such a makeover is expected to result in slower but more sustainable growth in the long run.

China in March set its annual growth target for this year at about 7.5 percent, the same as last year.

The World Bank on Friday said it expects China's economic growth to moderate over the next few years, with GDP expansion to slow to 7.6 percent this year.