Three-body ionic-recombination reactions of Xe+/Br-/He leading to XeBr* excimers and their predissociation products (Xe* and Br*) have been studied by observing emission spectra in a He flowing afterglow. The branching ratios of XeBr(B) :XeBr(D):Xe(6s P-3(1),6p D-1(2)):Br(Sp) in the Xe+(P-2(1/2))/Br-/He reaction are 0.65:0.077:0.087:0.19, while those of XeBr(B) : XeBr(C):XeBr(D) :Xe(6s P-3(1)):Br(5s) in the Xe+(P-2(3/2))/Br-/He reaction are 0.87:0.12:0.0040:0.0014:0.0067, respectively. The large relative formation rate of XeBr(B) in the Xe+(P-2(1/2))/Br-/He reaction indicated that a breakdown of the ion configuration of Xe+ occurs significantly in the Xe+(P-2(1/2)) reaction. The XeBr(B) state is probably formed through multiple collisions with third-body He atoms, which cause a trajectory change from the entrance V[Xe+(P-2(1/2)),Br-] potential to exit V[Xe+(P-2(3/2)),Br-] ionic potentials via predissociation V(Xe*,Br) potentials. The large relative formation rates of XeBr(B, C) in the Xe+(P-2(3/2))/Br-/He reaction indicated that the ion configuration of Xe+ is conserved well in the Xe+(P-2(3/2)) reaction. The electronic state distribution of Br(Sp) in the Xe+(P-2(1/2))/Br-/He reaction is nonstatistical, providing any preference for doublet, quartet, or for particular J states. It was concluded that most of Xe* and Br* are formed via predissociation of vibrationally excited XeBr* at long internuclear distances above 20 Angstrom.