China's first-quarter corn imports surged to nearly the volume imported in the whole of 2011, as state buyers replenished reserves even while publicly downplaying the extent of the country's appetite for foreign grains.

The country's transition from being self-sufficient to becoming a net importer marks a major shift in global food trade and underpins U.S. corn exports.

In the first quarter, imports reached 1.74 million metric tons, more than 300 times the volume in the same period last year, customs data showed Monday. The U.S. accounted for 99.5% of the trade. In contrast, exports fell 50% during the period.

Imports for the whole of 2011 were 1.75 million tons, 96% of which came from the U.S.

Speculation that China was in the market last week for up to 500,000-1 million tons of U.S. corn drove Chicago prices up by about 3%.

However, state stockpilers declined to confirm the purchases, likely fearing that premature disclosures would inflate global prices.

China Grain Reserves Corp., or Sinograin, said Monday that its stance on corn imports was unchanged.

"Sinograin will import corn when there is market demand and the price is right," spokesman Cheng Bingzhou told Dow Jones Newswires, echoing comments last month by Sinograin general manager Bao Kexin.

Domestic analysts said global prices, currently about 5% lower than at the start of the year, are low enough to draw Sinograin's interest, but they acknowledge the state stockpiler has been "extra secretive" in its purchases this year.

"This is also because Sinograin is sensitive to how such news drives up domestic spot prices, which are already quite high," Zheshang Tianma Futures analyst Xu Wenjie said.

Spot corn at Dalian port is around CNY2,400/ton, already 15% higher than Sinograin's offer price for domestic corn after the harvest last fall.

Sinograin may have changed its overseas purchasing tactics as well, shifting from big, single orders to a series of small bookings to divert attention from the deals, an executive with a state grain trader said.

Officials said China's appetite for foreign corn, driven by a generational shift in diets, will likely rise.

China may step up imports as U.S. prices have fallen below local prices, Shang Qiangmin, director of the China National Grain and Oils Information Center, said.

-By Chuin-Wei Yap and Zhoudong Shangguan; Dow Jones Newswires; (8610) 8400 7704; chuin-wei.yap@dowjones.com

(END) Dow Jones Newswires

April 23, 2012 03:52 ET (07:52 GMT)