Structured peer-to-peer (P2P) overlay networks provide a scalable object location and routing substrate for large scale distributed applications. However, due to the great number of nodes of such systems, message complexity of their routing protocol may considerably increase network traffic and average node hops of a message. This paper presents a novel Pastry-based routing protocol for structured P2P systems, which is specially suitable for handling per node multiple message routing requests. Our protocol exploits message aggregation and implements a multi-slice mechanism which multiplexes the sending of aggregated messages. Experimental results on top of PeerSim show that our protocol can reduce the average number of node hops messages, and thus, the global traffic and load of the network.