X0304 4 2011-10-27 0001084755 ARIBA INC ARBA 0001183228 CALDERONI ROBERT C/O ARIBA, INC. 910 HERMOSA COURT SUNNYVALE CA 94085 1 1 0 0 Chairman and CEO Common Stock 0 I Through 401K Plan Common Stock 2011-10-27 4 A 0 126237 0 A 510438 D Common Stock 2011-10-27 4 A 0 346022 0 A 856460 D This transaction reflects, with respect to the number of shares reported, achievement of the fiscal year 2011 performance goals applicable to the reporting person's fiscal year 2010 Performance Stock Unit award. Service-based vesting conditions continue to apply to this award. This transaction reflects with respect to the number of shares reported achievement of the fiscal year 2011 performance goals applicable to the reporting person's fiscal year 2011 Performance Stock Unit award. Service-based vesting conditions continue to apply to this award. Robert Calderoni 2011-10-28