The increasing demand of data rate with limited available spectrum has motivated the researcher to find solutions which enable to cater the demands of future wireless networks. Cooperative communication is one of the solutions, which uses the cooperation of other terminals called relays to complete the communication. The node who overhears the communication cooperate with the source of information and re-transmit it towards destination is the key concept of cooperation. If many cooperators retransmit with uncontrolled power, it results in wastage of power and increased interference in the network. To achieve the fruits of cooperation, it is, therefore, very essential to choose the appropriate partner (relay) and adequate power level for all the pairs of source-relay in the network. Relay assignment and power minimization algorithm for multisource multi relay scenario is presented in this paper. The approach taken in this paper ensures that each pair of source-relay consumes minimum power, at the same minimizing the overall power consumption of the network.