Rain in part of the US Midwest lent some support to soybeans and corn, which was also slightly higher, as it raised the possibility of a slowdown in spring planting.

Chicago wheat edged up as rainfall also raised a question mark over the start of the US harvest, while import tenders by Egypt and Tunisia suggested renewed international demand.

Further weakness in the dollar also underpinned grains.

The most-active soybean contract on the Chicago Board of Trade was up 0.3 percent at $9.79-1/2 a bushel by 1154 GMT, after rising to $9.80-1/2, its highest since May 10.

The USDA said on Tuesday that private exporters reported the sale of 132,000 tonnes of soybeans for delivery to unknown destinations during the 2016/17 marketing year.

"Despite the high supply from South America usual at this time of year ... the US is continuing to hold its ground in the market fairly well at the moment," Commerzbank analysts said in a note.

Traders were also monitoring the weather outlook for the Midwest corn and soybean belt, with showers forecast in parts of the region in the week ahead raising the risk of some planting delays.

"Midwest rains still active, slowing late soy seeding in the south," the Commodity Weather Group said in a daily update.

CBOT corn added 0.2 percent to $3.68-1/2 a bushel, while wheat was up 0.5 percent at $4.26-1/2 a bushel.

Corn remained capped by swift planting progress in the United States last week, and by the weight of global inventories.

Wheat traders were awaiting the outcome of a tender being held by Egypt, the world's largest wheat importer.

A change to quality specifications, increasing protein requirements, was expected to reinforce the dominance of Black Sea origins like Russian wheat.

But Egypt's return to the market, along with fellow importer Tunisia, could signal an upturn in overseas demand after a lull during the harvest season in North Africa.