Complex sentence: The Routemaster was designed by London Transport and constructed at Park Royal Vehicles, with the running units provided by its sister company AEC, both companies were owned by Associated Commercial Vehicles, which was taken over by Leyland Motors in 1962.
Split into simpler sentences: The Routemaster was designed by London Transport and constructed at Park Royal Vehicles, with the running units provided by its sister company AEC. Both companies were owned by Associated Commercial Vehicles, which was taken over by Leyland Motors in 1962.