A single-phase LaMn3+delta perovskite with high surface area could be synthesized after air-calcining the hydroxide precursor at 650 degreesC and above. The precursor was easily obtained by dropping a mixed aqueous solution of La and Mn nitrates into highly basic aq NH3 with and without the presence of N(CH3)(4)Br. The addition of N(CH3)(4)Br was effective in increasing the specific surface area of the products as well as in stabilizing the colloidal solution of the hydroxide precursor.