Reuters earlier reported that the Singapore-based firm was set to announce a strategic partnership with a Japanese peer, after Olam, majority-controlled by state investor Temasek Holdings, halted trading of its stock on Thursday.
One of the sources said Mitsubishi had done extensive due diligence and had also looked at other strategic investments before choosing Olam. The people declined to be identified as discussions were private.
Olam, in which Temasek holds a 58 percent stake, will sell new shares to Mitsubishi as part of the transaction, in which Temasek's stake will be diluted. Olam's founding family will also cut its stake in the company, the source said.
In a stock exchange filing on Thursday, Olam requested a trading halt pending an announcement. A Mitsubishi official had no immediate comment and Temasek declined to comment.
Olam processes and sells foods such as nuts and spices, as well as raw materials such as cotton and rubber.