CBOT September soft red winter wheat was last 1 cent lower at $6.14 per bushel; K.C. September hard red winter wheat last fell 3-1/2 cents to $5.90-1/2, and MGEX September spring wheat gained 7-3/4 cents to $8.22 per bushel.
Seller was believed to be trading house CJ International with corn arrival in South Korea around Nov. 20, five days later than originally sought in the tender from the KFA's Incheon section.
If sourced from South Africa, the supplier has the freedom to provide only 52,000 tonnes.
The US Agriculture Department reported totaled wheat export sales for the week ended April 22 at 461,300 tonnes. Analysts' forecasts ranged from 200,000 to 750,000 tonnes.
Corn export sales totaled 1.075 million tonnes in the week ended April 22, USDA said. That was in line with analysts' forecasts that ranged from 500,000 tonnes to 1.6 million tonnes.
The corn can be sourced optionally from the United States, South America or South Africa.
Some 68,000 tonnes was purchased at an estimated $305.31 a tonne c&f for arrival in South Korea around Aug. 25, traders said. Seller was believed to be trading house Cofco.
Ukraine exported 6 million tonnes of corn to China between October 2020 and March 2021, 5.0 million tonnes to the European Union, 1.7 million tonnes to Egypt and 3.2 million tonnes to other destinations.
Ukraine harvested around 30 million tonnes of corn in 2020 and the economy ministry said the export would not exceed 24 million tonnes in 2020/21.
This year, heavy rains delayed the harvesting of Brazil's soy and affected the second corn season in big producing states, raising fears of domestic supply shortages, especially among meatpackers.
In a separate report on Monday, consultancy AgRural said drier weather helped farmers reap more of their 2020/2021 soybeans over the past few days.
Asking prices have risen by $23-$26 per tonne so far in January, reaching a record $256-$264 per tonne FOB Black Sea.
APK-Inform said earlier on Saturday that Ukrainian milling wheat export prices added $3 per tonne on Friday amid rising global prices after Russia said it would hike export taxes.
But farmers railed against the suspension last week and launched a strike, saying the full ban put downward pressure on production and forced them to temper investments.