The static allocation schemes have led to the problem of spectrum under-utilization. In many bands, spectrum access is a more significant problem than physical scarcity of spectrum, in large part due to legacy command-and-control regulation that limits the ability of potential spectrum users to obtain such access. Dynamic spectrum management allows adaptive allocation of spectrum to various users in a multiuser environment as a function of spatiotemporally varying physical environment. A Cognitive Radio Network is a multi-hop multi-channel network with dynamic channel set for each user. Establishing a selforganizing cognitive radio network requires extensive exchange of control messages, needed to coordinate various network functions such as cooperative sensing, channel access, topology management, and routing. In wireless networks, control messages are broadcasted over a channel known to all nodes, commonly referred to as the common control channel. The concept of a single frequency band as control channel is not practical. It is considered wise to form smaller group of secondary users such that the number of available channels that are common to them is maximum. This paper deals with the methodology of obtaining the optimum groups. The major thrust of this paper is on the formation of the groups in such a way that graceful tradeoffs is achieved between the number of nodes in a group and the number of idle channels common to all the members of the group. Keywords— Cognitive radio network, control channel, idle channels, graceful tradeoff, clustering.