Brazilian mining mammoth Vale SA (VALE) is looking at further acquisitions of potassium assets, the Estado news agency reported Thursday.

Citing market sources, Estado said Vale was targeting Mosaic Co. (MOS), which is controlled by Cargill Inc. and IMC Global Inc. (IGL).

Vale on Thursday declined to comment on the company's alleged interest in Mosaic.

Mosaic is valued at $25 billion, Estado said; it is the world's largest phosphates producer and one of the world's largest potassium-mining companies.

Earlier this year Vale paid around $850 million for potassium-mining assets in Argentina and Canada.

Vale Chief Executive Roger Agnelli has previously said Vale is interested in developing its potassium-mining business to provide for Brazilian agriculture's large and growing appetite for fertilizers.

According to the Estado report, Vale's global mining rival BHP Billiton Ltd. (BHP) is also likely to compete for Mosaic.

-By John Kolodziejski, Dow Jones Newswires; 55-21-2586-6086; john.kolodziejski@dowjones.com