The deal comes soon after the company announced that its first franchised distributor in Europe will be Minorplanet Systems SAS in France.
Minorplanet Group says the deal will provide it with a healthy profit as the new French business will buy units from it.
Sernam will equip its vehicles, which includes cars and vans, with Minorplanet's Vehicle Management Information (VMI) system by January next year.
Minorplanet Systems chairman Michael Abrahams said: 'Earlier this year the group announced that it would focus on cash generation with the introduction of a franchise distribution system for certain countries in Europe.
'This franchising deal in France delivers on that commitment. Also, we are delighted that Minorplanet SAS has won from Sernam what is believed to be the largest fleet management system order by a single customer in Europe.
'Sernam, majority owned by French rail operator SNCF, is the biggest distributor in France.
This order demonstrates the success resulting from our world leading VMI technology.'
The system is not only used to locate vehicles for private and business use, but it also acts as a management reporting system, promising better management and cost reductions in business, Minorplanet claims.