Autonomous robots, such as robot office couriers, need con-trol routines that support flexible task execution and effective action planning. This paper describes X FRM LEARN,a system that learns structured symbolic robot action plansfor navigation tasks. Given a navigation task, X FRM LEARN learns to structure continuous navigation behavior and represents the learned structure as compact and transparent plans.The structured plans are obtained by starting with monolithical default plans that are optimized for average performance and adding subplans to improve the navigation performance for the given task. Compactness is achieved by incorporating only subplans that achieve significant performance gains.The resulting plans support action planning and opportunistic task execution. X FRM LEARN is implemented and extensively evaluated on an autonomous mobile robot.