Vauxhall aims to protect margins and values in its used cars by cutting the number of rental companies it supplies from 10 to four.

The manufacturer said it will halve the number of vehicles going into rental this year compared to 2008. It follows a 25% cut in rental volumes two years ago.

Vauxhall is unwilling to reveal which rental companies are affected. Hertz, Avis and Europcar said they were not affected.

Vauxhall managing director Bill Parfitt said the decision was taken because of the fall in the value of sterling against the euro, which has hit profits and the hit suffered on residual values.

“We have restructured to reduce the number of used Vauxhalls in the market and we have seen our residuals increase,” said Parfitt.

“Reducing our partners from 10 to four is a deliberate policy so we can better manage that business.”

The change could drive rental companies to extend replacement cycles, meaning dealers will have fewer low-mileage nearly new cars and LCVs to contend with.