Marubeni Corp. agreed to buy Gavilon Group LLC, the third-largest U.S. grain merchandiser, for $3.6 billion in what would be the Japanese company’s biggest deal.

“Marubeni’s purchase of Gavilon will give it an inroad into grain purchases in the U.S. and put it on par with the leader Cargill,” said Justin Tang, a Singapore-based analyst at Churchill Capital. “The performance of the stock today is reflective of investors’ positive expectations.”

Gavilon traces its roots back to Peavey Co., acquired by ConAgra Foods Inc. in 1982. Gavilon took its current form when ConAgra sold its trading and merchandising operations in 2008 to a group including Ospraie Management LLC, the commodities hedge- fund firm founded by Dwight Anderson, for $2.75 billion including debt.

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