Glencore International offered to buy Canada's largest grain company, Viterra, for $5.3 billion, the Sunday Telegraph reports.

Glencore Chief Executive Officer Ivan Glasenberg said the offer aims to add Viterra to the former's expanding grain business while it is completing the takeover of a Swiss metals and coal producer, Xstrata, in what is considered the largest mining takeover in the world.

Glencore and Viterra also operate from Australia. In 2009, Viterra purchased ABB Grain for $1.6 billion.

The bid from Glencore led Viterra to report to the Toronto Stock Exchange (TSX) on Friday that it got an unsolicited expression of interest from third parties. Glencore's offer is considered timely because the Canadian Wheat Board's market monopoly was ended in 2011 by Ottawa. Viterra currently controls 45 per cent of Canada's grain handling market.

Following the Viterra TSX statement, shares of the company went up to C$13.58 in Toronto on March 9, improving the company's market value to C$5.05 billion.

Glencore's agricultural unit has control over 8.7 per cent of the addressable global grain market, while its agricultural business enjoyed a sales of $9.9 billion in 2011.

Due to Glencore's Australian grain assets, the planned buy-in by the Swiss commodities trader is expected to attract the attention of the Australian Competition and Consumer Commission (ACCC). Glencore owns a local grain trading business and a 13 per cent share of AACL, an agricultural investment firm in Australia.

The ACCC concern could be over the oversized market since more than 40 marketers have emerged in Australia after the sector was deregulated.