GLOBAL commodity giants Glencore International and Cargill are believed to have each expressed an interest in buying Viterra.
The Canadian grain business' board was forced to disclose to Toronto Stock Exchange on Friday it had received expressions of interest from "third parties" after reports circulated that Swiss commodity trader Glencore had made a bid for the company.
The Wall Street Journal reported at the weekend US agribusiness Cargill was also interested in taking over Viterra.
Viterra share prices on the Toronto exchange jumped from $C11 ($A10.10) to $C13.58 ($A12.47) after the company's board made the disclosure, valuing the business at $C5.05 billion ($A4.6 billion).
By comparison, Glencore is valued at about $A30 billion, while Cargill is smaller at $A25 billion. Australia's biggest grain business, GrainCorp, is valued at $A1.4 billion.
Any takeover of Viterra would have big implications in Australia, where the Canadian company owns most of the grain storages and all of the port grain terminals in South Australia, plus storage and processing sites in Victoria.
It also owns Joe White Malting malting plants in every Australian state except Queensland.
Glencore took over Brooks Grain in July, 2005, and has since taken a significant stake in Australian agricultural investment company AACL.
Cargill bought AWB from Canadian fertiliser business Agrium Inc. in December 2010.