This study aims to develop an Automatic Generation Control (AGC) algorithm that enhances load-frequency control performance for multi-Area power systems taking the network splitting conditions into account. The AGC algorithm includes adaptive control capability for increasing the network Area Control Error (ACE) performance and manages multiple operation states for robust real-Time frequency control operations. Basically, in case of a network splitting, the algorithm evaluates conditions of generating units and determines manageable control areas based on the sufficient reserve availability. The operation and performance of algorithm are verified during and after the splitting without an interruption via software-in-The-loop simulations. During this study, the simulation and test platform including a real time power system simulation platform, a graphical user interface, and a communication interface are built and used in order to evaluate the proposed algorithm.