A global ocean general circulation model with sigma coordinates ispresented. It is designed for very long integration periods. Accordingly, itsnumerical technique is very efficient using implicit timestepping andoperator splitting methods. The model is driven at the surfaceby wind-stress and by restoring temperature and salinityto the observed annual cycle. The models cyclo-stationary solution dependson the initial conditions even after many thousand years of integration.Four different solutions are briefly reported in this note.The existence of multiple equilibria has been reported previouslyonly under mixed boundary conditions. Our findings imply that great caremust be taken when the sensitivity of the oceanic circulation is studiedor when data assimilation techniques are considered.