Chicago wheat fell on Wednesday, pressured by a U.S. Department of Agriculture (USDA) report giving a better picture of U.S. wheat condition than some expected.

Corn rose to its highest in almost a week on talk U.S. farmers may plant more soybeans instead of the corn sowings they previously planned. Soybeans were lower, in turn weakened by prospects of larger U.S. sowings, but saw some support from rain hindering Argentina's harvest.

The Chicago Board of Trade's most-active May wheat contract fell 1.1 percent to $4.68-1/2 a bushel at 1006 GMT. Most active May corn rose 0.1 percent to $3.57-1/4 a bushel, the highest since March 31. Soybeans fell 0.1 percent to $9.03-3/4 a bushel.

"The main focus of the market today is wheat which is seeing a sharp fall after the U.S. crop conditions report on Tuesday were better than some had feared," said Frank Rijkers, agrifood economist at ABN AMRO Bank. "Wheat has seen some strong support in the past couple of weeks because of concern about dry, cold weather in parts of the United States, but the crop conditions reports indicate that U.S. wheat is doing pretty well after all."

The USDA on Tuesday rated 59 percent of U.S. winter wheat as in good to excellent condition. That was above analysts' estimates for 57.6 percent of plants for summer 2016 harvesting, and the five-year average of 42 percent.

"Wheat supplies in other parts of the world are good, including Europe," Rijkers said. "There is a lot of wheat in the world and only moderate demand."

"Corn is seeing support from expectations U.S. farmers could plant less corn than forecast, turning instead to soybeans because of rainy weather during the U.S. sowing period. There is also support coming from belief that Brazil's corn exports will slow down and the country could even import corn after the surge in Brazil's corn exports at the start of this season."

Rainy, cool weather in the U.S. South and Midwest could prompt growers to switch 1-2 million acres of land to soybeans from corn, some estimates say.

In an early start to Brazil's grain export season, soybeans have overtaken corn at the country's ports in March and are expected to dominate bulk loading for the coming several months, trade data showed.

"Soybeans have little impetus today, but are seeing some support from concern that rain in Argentina could delay soybean harvesting," Rijkers said.

Argentine soybean harvesting in main production regions was halted by rain last weekend.