International Grains Council Thursday cut its estimate for world 2011-12 corn output by 4 million metric tons to 845 million tons due to diminishing prospects for the U.S. harvest.

The London-based body reduced its forecast for this year's crop in the world's largest corn producer by 10 million tons from its previous estimate to 315 million tons--which would be the smallest crop since 2008-09.

And despite a 4 million ton upward revision to prospects in both Brazil and Argentina, which are now expected to produce a total of 95.2 million tons, the IGC said world consumption is still expected to outstrip supply in 2011-12.

"The further downward revision in the U.S. maize production forecast is only partly balanced by an enhanced outlook for crops shortly to be planted in South America," it said.

Still, improving prospects for the world wheat crop, which was revised up by 2 million tons to 679 million tons thanks to "upward revisions for Russia, Ukraine and Australia," means "there is little overall change in the 2011-12 supply and demand outlook," said the council.