The vehicles will meet growing demand for the prestige end of the firm's flexible leasing product, Mini Lease, which offers a vehicle on short-term contract with no early termination penalty.
Under the three-year agreement, Mercedes-Benz will become the principal prestige model on the 3,000-vehicle fleet.
A key area of demand for Mini Lease is in providing pre-contract cars for employees awaiting delivery of their company cars.
The Mini Lease range includes all models, from A-class hatchbacks to the AMG sports range.
Nick Ratcliffe, general manager of corporate sales at DaimlerChrysler UK, added: 'Mini Lease is an innovative product offer in the corporate sector and this relationship demonstrates our enthusiasm to work with companies and service providers.'