We study nonequilibrium phenomena in a globally coupled oscillator sys
tem with a third harmonic pinning force in the presence of an additive
noise and a fluctuating interaction. The system shows a subcritical s
addle-node bifurcation from an asymmetric state to a symmetric state a
t a critical noise intensity leading to multistable states. The fluctu
ating interaction increases the critical noise intensity and thus enha
nces the multistability drastically. We show phase diagrams and discus
s the nature of the phase transition.