National Car Parks diversified into London contracted bus operations in 2005 under the NCP Challenger name. It already had its own operations based on shuttles to its car parks. Australian bank, Macquaries, owners of the East London Bus Group, acquired the car park operations in 2009 but the Challenger operation was hived off as NSL. Few buses got to acquire that fleetname before Transdev London United acquired the bus operation later that year. The buses have since been branded London United RATP when RATP acquired part of Transdev's London operation in 2012.