An uncertain recovery in the United States also weighed on shipments of electrical and electronic products, which make up about a third of Malaysia's exports.
Exports likely contracted 2.7 percent in October from a year ago, down from September's 2.6 percent year-on-year expansion, the median forecast of 16 economists showed. Shipments in August were the lowest in three years.
The forecasts for October exports ranged from a growth of 3.1 percent to a 7.6 percent decline.
Malaysia, like several other countries, traditionally enjoys stronger export growth in October due to year-end festive demand, but the tepid global environment has clouded the outlook for the trade-dependent country.
"A poor outcome is on the cards this Friday," said DBS economist Irvin Seah.
Shipments of Malaysia's top commodities including liquefied natural gas likely fell, economists said. Softer global prices also weighed.
Still, the economy has maintained strong growth on the back of robust domestic demand and government spending ahead of a national election that must be called by April.
Imports probably rose 11.0 percent year-on-year in October, the poll showed, higher than the 9.6 percent growth in the previous month.
The trade surplus was estimated at 7.2 billion ringgit ($2.37 billion) improving from 6.5 billion ringgit in September.
"The strong domestic demand would continue to prop up demand for imports, boosted mainly by consumption goods and capital good components," said Gundy Cahyadi, an economist with OCBC in Singapore.
Third quarter gross domestic product expanded 5.2 percent from a year ago, making Malaysia one of the fastest-growing economies in Asia. (Reuters)