Broker network Cobra said this week it is expecting to represent £200m in gross written premiums by the end of January 2004.
Joint-founder broker Truman Lincoln confirmed that 22 brokers had "fully signed up" to the network, while a further four were in the final stages of due diligence.
Cobra currently accounts for £100m in gross written premiums, but aims to double in size early in the new year.
Truman Lincoln managing director John Lincoln said: "We expect to have a further 30 members on board by the end of January."
Early growth at the network has exceeded expectations since it was jointly established by brokers Truman Lincoln and BKG in April this year.
At its launch, Cobra said it planned to represent combined premium income of £250m by April 2005.
Cobra said members' individual business independence, including insurer agency agreements, was guaranteed. There is no annual membership fee.
Among the larger brokers to have joined Cobra are Reason & Co in East Sussex, Hertfordshire-based ADS Insurance and Chris Semmens, and Crest Insurance in Worcestershire.
Lincoln said the 30 new brokers expected to join Cobra each represented premium income of around £1m-£10m.
Members of Cobra are given assistance on compliance issues as well as direct access to the network's insurer panel, which includes Allianz Cornhill, AXA, NIG, Norwich Union and Zurich.