Reuters: Royal Dutch Shell PLC RDS.A-N plans to make the biggest-ever foray into biofuels by an oil major, striking a deal with Brazil’s Cosan SA Industria e Comercio to form a $12-billion (U.S.) ethanol joint venture that will be the No. 3 fuel distributor in Latin America’s largest country. The deal, announced on Monday, marks Shell’s entry into ethanol production and follows moves by British oil company BP PLC BP-N , which in 2008 took a stake in a big Brazilian biofuel project and unveiled …