Lythgoe Motor Group has split from its owner Rob Lythgoe in a management buyout.
Mark Beach, who has worked at Lythgoe for 12 years, has taken over the Bolton-based business for an undisclosed sum.
Former managing director Lythgoe will leave the company to pursue other interests.
Beach said: "I am confident with the team we have at Lythgoe Motors that we can continue the success of the long-standing business and look to grow and develop in coming years."
With a turnover of more than £40m, the Lythgoe group has nine sites with Mazda, Citroën, Fiat and Nissan franchises.
It has just terminated a contract with Kia for its two sites in Wigan and Oldham. Kia said Lythgoe was moving in “a different business direction” to itself.