Shell and Cosan have signed binding agreements that will see the two companies form a $12bn (£8bn) joint venture to produce ethanol from sugar cane.
In addition, they plan to distribute a variety of industrial and transportation fuels through a combined distribution and retail network in Brazil.
The joint venture also plans to explore business opportunities to produce and sell ethanol and sugar globally.
With total annual sales of about 18bn litres of fuel, the proposed joint venture would have a competitive position in the Brazilian fuels-distribution market, built upon a network of about 4,500 retail sites.
With the terms of the joint venture agreed, Shell and Cosan, which remain as competitors, will now focus on securing regulatory approvals.
Neither Cosan nor Shell will contribute their lubricants businesses to the new venture.