The Citroen-only fleet consists of 185 cars, mainly the C5 and the Xsara, and 265 Berlingo and Dispatch vans.
The vans deliver vehicle parts across the UK from LSUK's 63 outlets while sales representatives and management use the cars.
The contracts will be run on a three and four year basis. LSUK has already replaced its fleet of cars while the vans will be in place by the end of the year. Springfield Cars in Gateshead supplied the vehicles.