The 20-year-old Argentine will play for the Blaugrana's 'B' team until 2014, but an option to secure a permanent deal has been written into the contract
Barca, who are yet to confirm the deal themselves, will insert a clause into Araujo's contract which will allow them to purchase the player for an undisclosed fee, should they see fit.
The 20-year-old has largely featured for Xeneize in the Copa Libertadores and the Copa Argentina since breaking into the first-team squad in 2009, and will move to Catalonia as a result of a recently-established link between the Blaugrana and the 2011 Apertura champions.
He will represent the Catalans' 'B' team next season, and will join fellow new signings Joan Angel Roman, David Lomban, Agostinho Ca and Edgar Ie.
The senior Barcelona team host Real Sociedad in their first La Liga match of the season on August 18.