The median forecast of 11 economists suggested exports, the main driver of Taiwan's economic growth, would slow from August's annual pace of 10.5% to mark the weakest performance since May's 3.5% rise.
September exports were expected to have totaled a record US$21.6 billion, up from $17.2 billion a year earlier.
"Soft US orders are capping headline growth, despite robust shipments to Europe and China expected due to year-end seasonal demand," said Tony Phoo, an economist at Standard Chartered.
Fewer working days in September compared with a year earlier would have dragged on exports growth, Ma Tieying, an economist at DBS, said.
The Mid-autumn Festival was celebrated in September this year, but October last year. In addition, the north of Taiwan was shut down for a day in September owing to a typhoon.
"Combining September together with October, exports growth should remain steady at around 10% year-on-year," she said.
US exports have logged annual declines in several months this year. Economists said they expected US demand to remain weak because the housing downturn will sap the strength of the world's biggest economy.
Taiwan's annual export orders in August, an indicator of future exports, eased to 16.3%.
Taiwan probably imported 10% more goods in September than a year earlier, swinging from a decline of 0.3% in August's figures.
The island's trade surplus was seen at US$2.6 billion, the poll showed, slightly narrower than US$2.8 billion a year earlier.
China and the United States are Taiwan's biggest export markets, taking up about half of exports. Electronics is Taiwan's biggest earner, accounting for more than a quarter of its exports.
Taiwan makes about 80% of the world's laptops and around 40% of flat panel displays. (Reuters)
