Dimerization equilibrium of the title compound is investigated in bulk and in an AOT aqueous pool in the presence and absence of urea by simple spectrophotometric determinations. The association in bulk is decreased by the addition of urea and strongly favored in reversed micelles with or without urea. The decrease in bulk media is assigned to a direct involvement (enthalpic) of urea in bridging the two phthalocyanine moieties whereas in the micelle electrostatic and volume confinements drive the equilibrium to the dimer species.