It is buying 250 Signums, which means that customers will be able to choose from a total of 56 different vehicle models from any of Enterprise's 220 UK outlets.
James Patmore, vehicle acquisition manager for Enterprise in the UK, said: 'Vauxhall's new Signum is a very distinctive product that extends our range of vehicles. Anything that adds to customer choice has got to be good.'
Vauxhall fleet sales director, Maurice Howkins, added: 'We have been business partners with Enterprise for many years. The fact that it is the first to take new Signum is a welcome extension of our great relationship.'