GrainCorp in Australia on Friday requested that its shares be placed in a trading halt after ADM took a large stake in the company.
The ABC reports two large blocks of GrainCorp shares, both worth around 10% of the company, were purchased before the start of trade on Friday morning.
The trades were made at $A11.75 per share, a premium of 33% to to the closing price of $A8.85 on Thursday.
The ABC reports there is speculation about a takeover bid.
However, GrainCorp did not specify the size of ADM's purchase and said it had not yet received a formal proposal from the American company.
According to its website, Archer Daniel Midlands is one of the largest agricultural companies in the world. Its headquarters is at Decatur, Illinois, in the United States.
ADM has 30,000 employees and more than 270 processing plants.
In May, GrainCorp reported a net profit of $A133.7 million for the six months to 31 March, up 52.5% on the previous corresponding period figure of $A87.7 million.
AAP reports the company said in May that it expected to make a full year net profit of between $A185 - $A205 million.