Insurer RSA booked a £50m loss over the recent hurricanes in the US and Caribbean, but said markets were "largely unchanged" elsewhere in the third quarter.
The group reported year-to-date net written premiums of £5.1bn in the third quarter, up eight per cent from the same period of 2016.
UK premiums rose five per cent to £2bn and premiums in Ireland were flat at £232m.
RSA said earnings per share in the year so far were ahead of 2016, but held back by third quarter underwriting results.
The FTSE 100-listed firm's update this morning was upbeat, but the group admitted that while "insurance and financial market conditions are largely unchanged", this excepted challenges in wholesale and international commercial markets from US and Caribbean catastrophe activity.
"The impact on market pricing trends from these events is as yet unclear," the firm said. However, UK underwriting results were hit by US/Caribbean hurricane costs, and RSA said its weather losses during the quarter included a provision of £50m for those storms. The insurer added that underwriting results were also weaker due to "continuing adverse household and large loss experience".
And investors seem to be wary about the numbers released this morning - shares were down 2.3 per cent at the time of writing.
RSA is not alone in dealing with ongoing problems after extreme weather across the pond. Insurer Lancashire Holdings dropped 3.6 per cent this morning after reporting a pretax loss of $136.4m (£102.8m), largely down to the effects of hurricanes Harvey, Irma and Maria, as well as the earthquakes in Mexico.
"The progress at RSA overall leaves group profits ahead of the same period in 2016 though by less than we had targeted," said group chief executive Stephen Hester.
"We are continuing to drive business enhancements across the group, whilst taking further underwriting action in some portfolios to improve performance for 2018."