Meeting full-year targets, according to CEO Christian Mumenthaler, is "highly dependent" on how financial markets perform and the outcome of large claims, such as those for hurricanes and other natural disasters, later this year.
A net profit of $157 million in the first six months compares to a net profit of $1 billion the previous year. It outperformed analysts' expectations of a $62 million profit.
The Zurich-based reinsurer recovered from a pandemic-related loss in 2020 last year, but the war in Ukraine has become a major headwind for the reinsurer, with reserves set aside for the war during the first three months of the year.
Despite this, the reinsurer said it returned to profit in the second quarter, helped by a drop in pandemic deaths.