Plymouth-based broker network Westinsure is set to exceed its £150m gross written premium target for 2006.
Director Denis Morgan said the alliance had lined up a string of new members across the South West during its latest promotional campaign.
Cornwall-based R Norman & Co, Prior & Co, Devon-based Plymstock Insurance Centre and Somerset-based Reedways Insurance have joined the alliance since March.
Morgan said: "The four brokers are trading at about £6m gross written premium and take our GWP to in excess of £110m. We have a target of £150m GWP this year."
Last year Westinsure targeted brokers placing between £1m and £6m GWP. This has now been expanded to between £500k and £8m.
According to Morgan, the strategy has worked and a further four brokers are expected to sign up to the network by the end of July.
"It is our aim to perpetuate the ability of small brokers, because if you move forward ten years there will only be the big consolidators left," he said.