Coincidence measurement was made in the reaction Ca40(Ne20,O16α) at 260 MeV incident energy, and the experimental results were analyzed in terms of the projectile breakup scheme. The reaction can be conveniently classified into the elastic- and inelastic-breakup processes. Comparison of the present results to those of the O16-singles measurement indicates the importance of the process in which the breakup is followed by the fusion process. Theoretical analysis shows that the main aspects of the present experimental results are explained. NUCLEAR REACTIONS Ca40(Ne20,O16α) E=260 MeV measured coincidence energy and angular correlations. Deduce reaction mechanisms. Calculations of elastic breakup and breakup-fusion processes.