Desira Group has acquired MR King and Sons Peugeot and Suzuki in Lowestoft.
The dealership at Horn Hill increases the total number of branches operated by the plc to nine and employees to 254.
Suzuki is a new franchise addition for Desira.
The deal sees its Peugeot representation increase to two. It is also a PSA parts hub for Norfolk.
Stuart Stone, managing director, said: "Desira Group is always looking to improve and grow within our marketplace. We felt MR King and Sons Peugeot and Suzuki was the perfect opportunity to further expand our group - offering our customers, a wider variety of products, services, choice and exceptional care.
"Also, we’re due to celebrate our 45th anniversary this year so it seemed the perfect time to be expanding the business."
Desira Group has eight other dealerships throughout East Anglia and one site in North West London, employing around 240 staff.
It represents Fiat, Nissan, Citroen, Peugeot, Jeep, Alfa Romeo, Abarth, SsangYong and Infiniti.