Swinton is set to boost its online presence after merging with its online sister company, its4me.co.uk.
The deal will make Swinton the largest independent UK broker, with access to 2.25 million policyholders, more than both the AA and Budget.
Its4me.co.uk has handled more than 26 million quotes online since its inception in February 2000.
Patrick Smith, chief executive and chairman of its4me and Swinton, said: "It makes great sense for the two businesses to merge. It allows the group to offer a fully integrated online and offline service to our customers.
"The deal continues the growth strategy of Swinton."
The merger comes just months after Swinton bolstered its high street presence by acquiring Budget's retail network.
The broker will begin rebranding Budget at the beginning of 2007. Smith said there would be no office closures as a result of the acquisition.
Last year, Swinton generated a gross premium income of £440m which it expects to grow to more than £600m.