Bermudan-based Endurance Specialty Holdings has bought the majority of Hartford Financial Services Group's reinsurance operation.
Endurance claimed the acquisition of HartRe would boost its level of premium income by $400m (£246m). Endurance generated $765m (£471m) in premiums in 2002.
Endurance is one of a handful of rapidly growing reinsurers set up in Bermuda to take advantage of soaring premium rates.
A year ago Endurance bought some of the business of LaSalle Re, a unit of struggling reinsurer Trenwick Group.
The deal follows Hartford's announcement last week that it plans to quit the reinsurance sector.
