The world’s top producer of concentrated phosphate has entered talks to buy Vale SA’s fertilizer unit. The move is part of an effort by Mosaic to grow its business in South America and Africa, according to Reuters. Both companies are still discussing the structure of a potential deal and seem to prefer a cash and stock agreement. Vale SA’s fertilizer unit, based in Brazil, is estimated to be worth $3 billion in the proposal. Mosaic’s CEO in February said the Minnesota-based company was “on the lookout” for phosphate or potash assets that could be bargain-priced in a weak commodity sector. Vale has fertilizer assets in five different countries, including Argentina, Brazil and Canada. Brazil is the world’s fifth-largest fertilizer consumer and fertilizer demand in the nation is expected to grow twice as fast as global demand until 2025.