In this paper, we introduce and solve the multicast routing problem for virtual circuit environment without making any assumptions about the communication patterns, or about the network topology. By multicast we refer to the case were one source transmits to several destination the same information. Also, we allow arbitrary interleaving of subscription patterns for different multicast groups, i.e. the destinations for each group arrive at an arbitrary order and may be interleaved with destinations of other groups. Our goal is to make route selection so as to minimize congestion of the bottleneck link. This is the first analytical treatment for this problem in its full generality. The main contribution of this paper is an online competitive routing strategy that has an O(\log n \log ) d competitive factor where n is the size of the network and d \leq n is the maximum size of a multicast group.