Hardy Underwriting Group has announced it has bought 6,470,000 shares in the specialist Lloyd's insurer, Atrium Underwriting.
The £4.85m purchase, equivalent to a stake of 13.3%, was at a price of 75 pence per share.
Hardy said the investment in Atrium will allow it to participate in a diverse underwriting portfolio, taking advantage of the current strong rating environment.
Hardy said the deal will be completed when it has obtained regulatory consents to control the Atrium group. The company added that the consents have now been applied for and are subject to formal Lloyd's and FSA approval.