By Kirk Maltais

--Wheat for December delivery fell 6.3%, to $8.46 a bushel, on the Chicago Board of Trade on Wednesday, after it was confirmed that Russia would rejoin the Black Sea export corridor deal after previously stepping away from it.

--Corn for December delivery fell 1.5% to $6.87 1/2 a bushel.

--Soybeans for January delivery rose 0.4%, to $14.54 a bushel.

HIGHLIGHTS

Reprising Their Role: CBOT grain futures were jolted in morning pre-market trading, with wheat in particular selling hard on indications of Russia rejoining the Black Sea grain export corridor deal after previously declaring its exit from it. The Wall Street Journal reports that assurances from Ukraine that it wouldn't use the corridor to attack Russian forces helped end Russia's suspended involvement, and that vessels are soon to resume their previously scheduled travel. Grain traders say they are now looking at volumes being shipped from Ukrainian ports to see if they stay consistent.

Regional Instability: Corn and wheat futures on the CBOT were pressured by Russia's return to the Black Sea export corridor deal, but soybean futures were instead supported by turmoil in Brazil following the election of Luiz Inácio Lula da Silva for President - with supporters of his opponent Jair Bolsonaro blocking major roads in protest of 'Lula's' victory. "It's likely that markets are putting in a premium given the unrest in Brazil," said Jake Hanley of Teucrium. However, the current unrest isn't expected to be a lasting source of support for soybeans, Mr. Hanley told the WSJ. "It's growing season in Brazil, not export season," he said.

INSIGHTS

Open Question: Even with Russia opting back into the existing grain export corridor deal with Ukraine, whether or not Russia will extend the deal later this month remains unknown. "Still a lot of uncertainty as to whether this new agreement will hold when military hostilities continue unchecked," Joel Karlin of Western Milling told the WSJ. "It is now back in guessing mode as to whether there will be an extension or not." Traders expect that Russian President Vladimir Putin may use the looming end to the deal as leverage in negotiations, including those at the G20 Summit in Bali later this month.

Steady Sailing: Daily production and Inventories of ethanol in the U.S. made only marginal moves in the past week, with production returning to a level last seen in July. In its latest weekly report, the U.S. Energy Information Administration said that daily production of U.S. ethanol rose to 1.04 million barrels per day for the week ended October 28. This is up from 1.033 million barrels per day reported last week, and highest since late July. The total fell short of estimates from analysts surveyed by Dow Jones this week - who had forecast production to rise to as high as 1.057 million barrels per day. Ethanol inventories inched back for the week, with stocks totaling 22.23 million barrels, down from 22.29 million barrels last week.

AHEAD

--Zoetis Inc. will release its third-quarter earnings report before the stock market opens on Thursday.

--Ethanol producer Green Plains Inc. will release its third- quarter earnings report before the stock market opens on Thursday.

--Nutrien Ltd. will release its third-quarter earnings report before the stock market opens on Thursday.

--The USDA will release its weekly export sales report at 8:30 a.m. ET Thursday.

--Corteva Inc. will release its third-quarter earnings report after the stock market closes on Thursday.

Write to Kirk Maltais at kirk.maltais@wsj.com

Wheat Falls After Russia Returns to Export Deal -- Daily Grain Highlights

Wheat futures for December delivery fell 6.3% to $8.46 a bushel on the Chicago Board of Trade following Russia's return to the Black Sea export corridor deal. Corn futures fell 1.5% to $6.87 1/2 a bushel, while soybean futures rose 0.4% to $14.54 a bushel. The article discusses the implications of Russia's decision on grain markets, the ongoing political unrest in Brazil, and upcoming earnings reports from several companies.