Archer Daniels Midland Co. is expanding restructuring efforts as the agricultural company works to rebound from challenges due to bad weather and trade tensions.

The Chicago-based company on Friday said it plans to close aging flour mills, cut production of high-fructose corn syrup and prepare ethanol operations for a potential spinoff. Previously ADM had said it would reduce staff and streamline global operations.

Biting cold and damaging floods cut ADM’s first-quarter operating profit by $60 million, the company said, disrupting rail traffic, temporarily shutting a Nebraska corn plant and boosting costs for other facilities.

Overall, ADM’s quarterly profit fell 41%. Shares fell more than 2% in recent trading.

ADM and other global agricultural companies have faced several years of low crop prices that have slimmed commodity-trading margins. Over the past year, trade disputes have also disrupted agricultural export flows. In February, ADM reported a 60% drop in its prior quarterly earnings, after Chinese tariffs on U.S. crops reduced soybean exports and pushed down ethanol processing margins.

ADM Chief Executive Juan Luciano on Friday reiterated optimism that the U.S. and China would resolve their trade dispute this year. He said Chinese grain importers already were preparing to resume purchases, as they drew down existing supplies and reviewed purchase contracts with ADM.

“Everybody is inching toward a deal in the summer,” Mr. Luciano said.

Rival grain merchant Bunge Ltd. is pursuing its own revamp, evaluating its portfolio for potential divestitures and replacing executives, including its CEO. Other agricultural companies, including Cargill Inc. and Louis Dreyfus Co., have shuffled grain and supply chain executives in recent weeks. ADM last week appointed a new grain-trading head.

ADM executives said the company plans to reduce capital spending by 10% this year. It is creating an ethanol subsidiary that will report results as an independent business unit, allowing the company to potentially spin off the business to existing shareholders. Profits from the corn-based fuel additive have slumped by about 25 cents a gallon in recent months as inventories climbed and foul weather increased production costs, executives said.

ADM plans to cease high-fructose corn syrup production at its Marshall, Minn., plant, shifting instead to starches and other food and industrial products for which Mr. Luciano said demand is stronger.

ADM also said it would close several century-old wheat mills, sell some grain-storage facilities and overhaul its peanut operations. Overall, ADM aims to save $1.2 billion in annual expenses.

China’s eight-month struggle with African swine fever, prompting the destruction of millions of hogs in the world’s largest pork-producing nation, is set to boost ADM, Mr. Luciano said. Hog farmers in the U.S., Europe and Brazil are preparing to expand their herds to supply pork to China, requiring more corn, soybean meal and other feed ingredients that ADM supplies, he said.

ADM reported a first-quarter profit of $233 million, or 41 cents a share, down from $393 million, or 70 cents a share, a year earlier.

After adjustments, the company recorded earnings of 46 cents a share, weaker than the 60 cents a share analysts predicted.

Sales fell 1% in the quarter ended March 31 to $15.3 billion. Analysts expected $15.57 billion in sales, according to FactSet.