CHICAGO (Reuters) - Global grain marketers have seized upon trade tensions between the United States and several of its top export markets, including China, to turn around struggling trading units following one of the toughest years ever for the industry.

FILE PHOTO: The world's largest corn mill of global grain company Archer Daniels Midland is pictured in Decatur, Illinois, U.S., March 16, 2015. REUTERS/Karl Plume/File Photo

After five years of bumper harvests worldwide that depressed crop prices, trading margins are on the rebound. For Archer Daniels Midland Co, market volatility from the trade disputes, as well as a drought in South America, helped its trading unit report the best first-quarter performance in four years on Tuesday.

ADM and its rivals make money buying, selling, storing and processing crops. With networks of elevators, mills and processing plants around the world, the companies can capitalize on shortages in some geographies and surpluses in others.

Taking advantage of market gyrations could be a salve for ADM and its rivals Bunge Ltd and Cargill Inc [CARG.UL], as they cope with the risks to exports posed by the wave of trade protectionism, analysts said.

“Longer-term, open and free trade is important for the global grain companies, but the near term uncertainty that the trade issues are causing are creating merchandising opportunities,” said Farha Aslam, food and agribusiness analyst with Stephens Inc.

The company’s trading unit represents a fraction of ADM’s overall business. Following a recent restructure, its origination unit, which includes its trading business, earned $45 million in the first quarter of 2018, representing about 6 percent of the group’s operating profit for the quarter.

ADM Chief Executive Juan Luciano remained cautious on the future.

“We continue to closely monitor trade developments both in terms of NAFTA, as well as U.S.-China developments that seem to evolve almost on a daily basis,” Luciano said during an earnings day conference call, referring to negotiations over revising the North American Free Trade Agreement.

Growing trade disputes are disrupting the agricultural supply chain worldwide, from corn buyers in Mexico shifting purchases to Brazil, to ships carrying U.S. sorghum exports turning around after China slapped on hefty tariffs.

Overall, the United States exported $138 billion in agricultural products in 2017, according to U.S. Census data.

ADM rival Bunge reported its first quarter results on Wednesday. It did not give details on its trading unit, other than to say that it saw “higher results” in global trading and distribution due to increased margins. A change in the fortunes of its trading unit could help it fend off potential suitors. Bunge has been the subject of takeover talk from Glencore and ADM.

Bunge’s trading operation is a part of the larger agribusiness unit that also includes oilseeds and grain processing. In its fourth quarter results, it said margins for grains trading were “under pressure.”

Just a year ago, ADM was cutting costs and consolidating operations as it struggled with poor earnings. It now expects “significantly improved” results for its wider grain trading operations in the second half, boosted by dry weather affecting crops in Brazil and Argentina, it said on Tuesday.