Stuart Alexander has announced the acquisition of Bishop Skinner, increasing its premium to more than £60m.
The broker said the purchase represented a "springboard" for its expansion into the marine and small craft sector, while also boosting its commercial book.
The Bishop Skinner brand will not be relinquished completely, as the business will retain its identity for its marine accounts, but the general business will be renamed Stuart Alexander.
Stuart Alexander chief executive Stuart Reid said the acquisition had come one year since the company's leveraged buy-out and was just the beginning of its expansion plans.
He added: "We have access to funds to expand further by acquisition and are keen to talk to others who are looking to sell, particularly in the South."