In this paper, we suggest a simple and efficient multiple-forwarder-based file distribution method which can work with a tree-based application layer multicast. Existing multiple-forwarder approaches require high control overhead. The proposed method exploits the assumption that receivers join a session at different times. In tree-based application layer multicast, a set of data packets is delivered from its parent after a receiver has joined but before the next receiver joins without overlapping that of other receivers. The proposed method selects forwarders from among the preceding receivers and the forwarder forwards data packets from the non-overlapping data packet set. Three variations of forwarder selection algorithms are proposed. The impact of the proposed algorithms is evaluated using numerical analysis. A performance evaluation using PlanetLab, a global area overlay testbed, shows that the proposed method enhances throughput while maintaining the data packet duplication ratio and control overhead significantly lower than the existing method, Bullet.