Ultra-wideband (UWB) communications has emerged as a promising technology for high data rate wireless personal area networks (WPANs). Several proposals for UWB- based WPANs have been made. One widely popular proposal was standardized by ECMA-368, and is based on OFDM. In this paper, we address one of the important aspects that impact the performance of this standard, namely interference management between different uncooperative beacon groups operating simultaneously over the same area. We propose an interference management distributed reservation protocol (IM-DRP) for OFDM-based UWB communications. IM-DRP aims at improving the throughput achieved by WPANs by reducing interference between uncooperative beacon groups. Computer simulations are used to demonstrate the performance gain of the proposed protocol.