Multicasting is an important feature for any switching network being intended to support broadband integrated services digital networks (B-ISDN). This paper proposes an improved multicast packet switch based on Lee's nonblocking copy network. The improved design retains the desirable features of Lee's network including its nonblocking property while adopting techniques to overcome the various limitations mentioned in various literature. The proposed network architecture utilizes d-dilated banyan networks to increase the amount of cells that can be replicated within the copy network. Cell splitting is used to optimize the utilization of the network's available bandwidth. Furthermore, the proposed architecture allows for the modular expansion in capacity to accomodate changing traffic patterns. The modular design of the proposed switch likewise offers easy handling and replacement of faulty modules.