Profits at Swiss Re, the world's second biggest reinsurer, have surged more than five-fold on the back of the stock market recovery and rising premiums.
The company said it made 691m Swiss francs ($489m; £310m) in the first six months of this year, up from 118m in the same period of 2002.
The much-improved figures are the result of the reinsurance industry's realignment following the 9/11 tragedy, which cost all the main players dearly, and the stock market slide since 2000.
The heavy losses they sustained in 2001 meant premiums across the sector rose this year, underpinning the gains at Swiss Re.
Munich Re, its larger rival, reported a fifth straight quarter of losses yesterday, but said the better premiums meant a profit on its underwriting business, as was the case at world number five Hannover Re.
The contrast with last year is only partly the result of the rise in premiums, which according to Zurich Financial Services could now be running out of steam.
Unlike recent years, there has been no major claim to dig a hole in the results of reinsurance companies, which specialise in taking risk off the hands of front-line insurers.
And the turnaround on world stock markets this year has also played a part, with most major equity indices up sharply on where they were this time last year.
In the first half of 2002, Swiss Re had to write off 917m francs on its investments.
But this year the Dow Jones Stoxx 50, a benchmark index for European shares, rose 14% in the three months to the end of June, compared with a 17% fall in the same period last year.