Car rental giant Avis is reuniting its US and European franchises 25 years after the European operation was spun off – and the newly-merged company will use the same IT systems it ran when the two arms first separated.

Avis Europe separated from the US-based Avis Budget in 1986 but remained on Avis Budget’s Wizard mainframe system ever since.

This technology loyalty should help with today’s announcement of a £636 million deal to reintegrate the European operation.

Last month, Avis Europe praised Wizard, which was introduced in 1972, as “the first and still the most extensive online, real-time reservation, rental and management information system in the industry”.

It is used by Avis globally to check customers in and out and to produce operational reports. Wizard also manages the Avis fleet of vehicles, and provides real-time data to thousands of agents and partners worldwide.

Avis Europe has been using the system as a sub-licensee since 1985, and has also worked collaboratively with the US to steer some of its development.

The European business also operates a central IT services model, led by former CIO Adam Gerrard, which enables greater sharing of technology and best practices. Although the company had not yet responded to requests for comment, it is expected that this model could be expanded to include the US business, to help deliver planned annual savings of $30 million (£18 million).

Ronald Nelson, chairman and CEO of Avis Budget, said: “The transaction re-unites the global operation of the Avis and Budget brands under one corporate umbrella, and is both financially and strategically compelling.

“We expect the combination of our two companies will allow us to more effectively serve vehicle-rental customers worldwide, and to achieve synergies of more than $30 million per year.”

The companies added that the merger will expand Avis Budget’s reach in growing international markets, such as India and China.

Avis Budget’s CIO and senior vice-president Gerard Insall could potentially oversee the merger since Gerrard last month left the European business to join, the online hotel booking aggregation service, as CTO. His replacement has not been announced.