Northgate Vehicle Hire is taking delivery of more than 2,000 new vans and cars this month.
1,500 of the vehicles have already been taken into the fleet, and the company is due to take a further 600 by the end of September.
Most of these new purchases are light commercial vehicles such as Ford Transits, Mercedes-Benz Sprinters, Volkswagen Caddys, Peugeot Partners and Vauxhall Astravans as.
This fleet extension follows a rebranding of the business earlier this month, from a network of 20 local individual brands to the creation of one national brand.