SHANGHAI/HONG KONG Oct 12 (Reuters) - China's daily imports of crude rebounded in September from the previous month to a fresh record, bearing out forecasts for the country to overtake the United States as the world's largest oil importer, as refineries restarted following maintenance.
Iron ore arrivals also surged to a record of more than 74 million tonnes as mills ramped up production, while copper shipments jumped 18 percent from August to hit their highest in 18 months, as end-users rebuilt inventories on a brighter economic outlook.
Soybean shipments fell to less than 5 million tonnes, however, as volumes fell back to normal levels after a surge in second-quarter imports due to the arrival of postponed cargoes.
"The recent upswing in China's economic activity has significantly boosted import demand for oil and other commodities," said analyst Li Yan at industry website Oilchem.net.
"But there are now concerns on whether the recent improvement in the economy is going to fade."
China's export growth fizzled in September to post a surprise fall, data showed, a disappointing end to a recent run of indicators that had signalled the world's No. 2 economy was gaining strength.
The Customs Administration said on Saturday China's exports dropped 0.3 percent in September on the year, sharply confounding market expectations for a rise of 6 percent, and marking the worst performance in three months.
Beijing has a growth target of 7.5 percent for 2013, which would be the weakest rate in more than 20 years, and has vowed to accept slower growth as it tries to reshape the economy so that it is driven by consumer demand, rather than investment, credit and exports.
Average imports of crude in September stood at 6.25 million barrels per day (bpd), up 28 percent on the year and topping the previous record of 6.15 million bpd set in July.
Net imports of 6.23 million bpd show that China overtook the United States in September as the world's biggest net oil importer, a trend which the U.S Energy Information Administration said would continue through 2014.
In terms of monthly tonnage, September imports of 25.68 million tonnes was the second-highest on record after July, bringing total shipments in the first nine months to 211.3 million tonnes, up 5.4 percent from a year ago.
Traders have attributed the monthly gain to a slew of large refineries going online after completing scheduled maintenance.
Copper imports by China, the world's top consumer of the metal, reversed the fall in August and jumped 18 percent in September, as importers boosted orders ahead of a seasonal pickup.
Imports of anode, refined copper, alloy and semi-finished copper products reached 457,847 tonnes in September, the highest since March 2012 and up 16 percent from a year ago.
Importers had bought more refined copper to replenish stocks in bonded warehouses, and on expectations of a seasonal pickup in September and October, said Zhou Jie, a trading manager at China International Futures in Shanghai.
Copper stocks in bonded warehouses have fallen about 60 percent from a record high of around one million tonnes in the year's first quarter, traders estimate.
Total imports of copper in the June-September quarter rose 21.4 percent over the second quarter to 1.256 million tonnes, data showed.
China, the world's top consumer of iron ore, imported a record 74.58 million tonnes of the steel-making ingredient in September, up eight percent from August and an increase of 15 percent on an annual basis, customs data showed.
Imports were driven by robust steel production, with daily runs above 2.14 million tonnes in the first 20 days of September, versus August's daily figure of 2.13 million.
But after a stellar run in the third quarter, imports are expected to weaken through the rest of the year, as steel demand typically falls in the winter, cutting demand for iron ore, said Jin Tao, an analyst with Guotai Junan Futures in Shanghai.
The strength of China's iron ore demand has caught the market by surprise this year, as an unexpectedly buoyant property market has propped up steel demand.
Steel production has gained 7.8 percent in the first eight months, more than double the growth of 3.8 percent forecast by analysts in a Reuters poll in July.
China, the world's top buyer of soybean, imported 4.70 million tonnes of the oilseed in September, a tumble of 26 percent from the previous month and a second month of decline as arrivals started to return to normal.
Monthly shipments are levelling off from a surge in second quarter deliveries caused by port-related disruptions.
Still, traders expect soy imports to pick up from November as crushers run at good margins and domestic demand improves.
Imports in the first nine months have risen 3.3 percent on the year to 45.75 million tonnes, customs data showed, as a fast-growing poultry industry boosts demand for soy meal and planting areas shrink as farmers turn to more profitable crops.
(Additional reporting by China commodities and energy team; Editing by Clarence Fernandez)