Collaboration among neighbouring eNBs in radio resource allocation, in the absence of a centralized control unit, is one of the challenges raised from the flat architecture suggested for the Long Term Evolution (LTE) networks. This paper investigates the system performance of a collaborative resource allocation scheme, in a scenario that consists of two tiers of collaborative Regions (CoR), and considers the gain achieved from the eNB collaboration and performance degradation due to the interference from neighbouring eNBs. Our results indicate that interference introduced from the cells outside the collaborating cluster can have significant impact on the system performance. However, Monte Carlo simulation based performance analysis demonstrates the effectiveness of collaborative resource allocation among adjacent eNBs for the LTE networks.