Automation of radio network management is a key determinant to work reduction for wireless operators. By replacing time consuming and costly tasks with automatic mechanisms, operational expenditure can be reduced. In this paper we present a method for automatic configuration of locally-unique physical cell identities and neighbor cell relation lists in 3G long term evolution (LTE). This method makes use of mobile measurements to update the neighbor cell relation lists in the cells and to detect local cell identity conflicts, report the conflicts to the operation support systems (OSS) and resolve them. The performance of the approach is determined using simulations of realistically deployed macro networks. Conducted simulations illustrate the ability of the method to resolve local cell identity conflicts. In particular, the method is capable of both accommodating new cells and handling a worst case scenario where all cells are initiated with the same local cell identities and where neighbor cell relation lists are empty.