Swinton Insurance Group has acquired Colonnade Insurance Brokers from parent Provident Financial for £27m, making it the UK's biggest high street insurance chain.
The group said the acquisition forms part of its parent's, MMA Holdings UK plc, growth strategy, which is going to continue.
Colonnade's 88 outlets will be added to Swinton's 260 high street branches and both brands will be maintained.
Swinton chief executive Patrick Smith commented: "This deal underlines our commitment to insurance broking through branch relationships.
"With 90% of mainland Britain now covered by a branch, we have an extra dimension to offer in competition with call centre operators."
Swinton has made 60 broker acquisitions in the last two years and expects its annual gross premium income to reach £400m this year following this purchase.