The £60m paid for the group was split - approximately £28 million for the entire issued share capital of Dutton Forshaw and £32 million of debt.
Lookers expects the deal to be earnings enhancing after its first full year of ownership.
The deal is expected to be completed by October 26.
Lookers said it expected to retain the vast majority of employees of Dutton Forshaw.
Dutton Forshaw has a network of 31 outlets operating under the Dutton Forshaw and Dovercourt brands.
The acquisition will increase the Lookers’ number of Ford outlets from one to eight, Mercedes-Benz outlets from four to eight and VW outlets from five to nine. Other outlets acquired include Chevrolet, Chrysler Jeep and Dodge, Citroen, Honda, Hyundai, Land Rover, Peugeot and Skoda.
In particular, the acquisition will strengthen Lookers’ presence in the south east and north west of England, and provide a foothold in south Wales.