Swiss Re's property and casualty underwriting squeezed under the magic 100% combined ratio barrier in the first half, reporting a ratio of 99.8%.
The sector produced profits of SFr822m (£370m), up from SFr104m in the same period of last year.
Swiss Re said its property and casualty operation was reaping the benefits of the hard market, with premium income up by 18% to SFr7.9bn or 33% in original currencies.
It said it was committed to "increasing the quality of its book during the 2003 renewals," raising the prospect of continuing pressure on its insurer customers.
The group's operating result of SFr691m was up from SFr118m last year.