This paper proposes a new multicast protocol for mobile ad hoc networks (MANETs). The proposed protocol, Shared-Tree MZR, is a shared tree variant of the Multicast Routing Protocol based on Zone Routing (MZR). The concept of zone-based multicast routing for mobile ad hoc networks was originally proposed in MZR. The new protocol utilizes the advantages of the shared-tree together with the advantages of the zone-based routing. The performance of the protocol is analyzed for various network conditions. The test results show that the new protocol performs well and has significantly low overhead in scenarios with multiple sources.