The solution of monopolar corona equation already reported in literature is extended for bundle conductors using a modified iterative procedure to estimate the corona current contributed by each subconductor of the bundle. The solution is based on underlying assumptions, some of which are waived in the present calculations. The variation of ion mobility with its lifetime as well as the change of the corona onset voltage from point to point on each subconductor are taken into account for the first time. The calculated corona currents from each subconductor are compared with those measured experimentally for a laboratory model.