Chicago wheat futures suffered a modest setback on Friday after rising to a one-month peak, with concern about high stocks helping to stall a rally driven by adverse crop conditions in the United States.

Corn and soybean prices gained as the outlook for U.S. exports received a boost from a strengthening in the currency of key rival Brazil.

May wheat on the Chicago Board of Trade was off 0.2 percent at $4.76-1/4 a bushel at 1200 GMT after rising to a one-month peak of $4.78-1/4.

Weather concerns included the expansion of abnormally dry conditions in some areas of the southern Plains hard red winter wheat belt and heavy rains in the Delta and southern Midwest, where farmers are preparing to plant crops, including corn.

"Reports of dryness in the (U.S.) Plains, and wetter conditions in the Midwest, which are potentially seen as delaying planting of U.S. spring crops, have resulted in bouts of short-covering," David Sheppard, managing director of UK merchant Gleadell, said.

"However, any rally is struggling against price resistance from the size of U.S. stocks, which provides a significant cushion against perceived lower new-crop production."

The U.S. Department of Agriculture (USDA) forecasts U.S. wheat stocks will be at a six-year high of 26.29 million tonnes at the end of the 2015/16 season.

May wheat in Paris rose 0.75 euro or 0.5 percent to 155.00 euros a tonne.

CBOT May corn rose 0.3 percent to $3.64 a bushel, boosted partly by the strength of Brazil's currency, the real , which has risen to a six-month high against the dollar.

"The real's strength is a plus for U.S. competitiveness - as evidenced by another strong week of U.S. corn export sales," Commonwealth Bank of Australia analyst Tobin Gorey said.

The USDA on Thursday reported net U.S. corn export sales last week topped 1 million tonnes for a fourth straight week, although season-to-date sales remained 20 percent behind the same point last year.

CBOT soybeans were also supported by the strength of Brazil's currency, with May up 0.6 percent at $8.94-1/2 a bushel after rising to a 2-1/2-month high of $8.95.