Corn heads for biggest weekly loss since July on abundant supply

CANBERRA, Jan 16 (Reuters) - Chicago corn futures edged higher on Friday but were still set to end the week down more than 5%, their steepest drop since July, after upward revisions to production estimates underscored abundant global supply.

Wheat and soybean futures also nudged higher, though ample supply capped gains, leaving both contracts on track for modest weekly losses.

The most-active corn contract on the Chicago Board of Trade (CBOT) Cv1 was up 0.2% at $4.21 a bushel at 0518 GMT but down 5.6% from last Friday's close.

Prices tumbled on Monday after the U.S. Department of Agriculture (USDA) lifted its estimates for U.S. production and inventories more than analysts had expected.

The International Grains Council highlighted expectations of plentiful supply on Thursday, raising its 2025/26 global corn production estimate by 15 million metric tons to 1.313 billion tons while also increasing its assessment of worldwide wheat output.

"Luckily the global animal protein sector is performing well and so they are buying more feed grain," said Rabobank analyst Vitor Pistoia.

However, U.S. exports will have to remain high through the rest of the season to avoid excess inventories, which may require U.S. prices to fall to out-compete Brazilian corn, StoneX analyst Bevan Everett wrote in a client note.

In other crops, CBOT soybeans Sv1 climbed 0.1% to $10.54 a bushel but were down 0.8% over the week, while wheat Wv1 gained 0.1% to $5.10-3/4 a bushel and was headed for a 1.3% weekly fall.

Soybean prices have been supported by strong U.S. domestic demand and a jump in CBOT soyoil prices, which rose 4.4% on Thursday and were up another 0.3% on Friday after Reuters reported that the U.S. government plans to finalise 2026 biofuel blending quotas by early March. BOc1

The U.S. National Oilseed Processors Association said its members crushed the second-largest monthly amount of soybeans on record in December, beating analyst expectations.

However, plentiful supply still weighs on prices. Crop agency Conab on Thursday projected record Brazilian soybean output of 176.12 million tons in the 2025/26 marketing year, and consultants Agroconsult said the crop would be an even bigger 182.2 million tons.