Brit is launching a new Bermuda reinsurer.
Norton Re will specialise in catastrophe retrocession business and has been licensed by the Bermuda Monetary Authority.
Norton Re is preparing for the treaty renewal season commencing on 1 January 2007.
Brit has a 19.6% stake in the reinsurer, having invested $21.1m of the initial $107.7m capital.
Dane Douetil, Brit chief executive: "We announced earlier in the year that we were investigating this new strategy and we are delighted by the high level of demand that we have seen from investors. As 2006 has progressed, terms and conditions and pricing in the retrocession market have strengthened further and we and our fellow investors regard this as the optimal time to launch the new carrier.
"Norton Re will offer investors pure exposure to this specialist underwriting area with the benefit of our knowledge and experience. Our own investment will be restricted to a minority share to limit correlation of risk with our other classes of insurance and reinsurance.
"This will be our first investment in an offshore underwriting business and a further significant step in Brit Insurance's evolution into a widely diversified insurance group. We believe that this innovative structure is attractive to capital markets and is a potential blueprint that we can consider for other classes of business with similar characteristics."