The leasing supplier has introduced its all-inclusive contract hire product at the firm, which includes fuel, vehicle maintenance, insurance and finance in one monthly payment.
By channelling all costs through a single supplier, the firm claims to have reduced its spending on the fleet, particularly by reducing the cost of its vehicle insurance.
The contract hire firm has taken over responsibility for maintaining the fleet of 46 Citroens and Peugeots.
The firm switched from a rival leasing company after examining costs and looking at the internet-based management package that Arma offered.
The internet link to Arma will also enable Timac to view all its company car details online, including fuel usage and cars on order.
Timac is a subsidiary of Roullier and supplies animal nutrients and fertilisers to farmers and merchant customers.
Liam Donnelly, managing director at Oxford-based Arma, a subsidiary of Arma Beheer based in Holland, said: 'In Holland 70% of Arma's 19,000 vehicles are delivered this way. UK companies which run company cars can save on administrative time and cost through working with a single supplier.
'We calculate companies will save up to 10% in costs over the life of the vehicle contract.' Arma will manage contact will all drivers on the fleet, which includes providing cost information following an accident.