Rising insurance premiums for commercial property and workers’ compensation pushed up aggregate commercial insurance prices in the US by almost 1.5% in the second quarter of 2010/11, according to a Towers Watson survey.

The commercial lines insurance pricing survey revealed increases across all lines after a flat first quarter. The only sector to show a decline in pricing levels was directors’ and officers’ liability.

The cost of insuring commercial property increased for the first time in five quarters, “likely influenced by the catastrophes early in the season”, the report says.

The third quarter, following yet more natural disasters, is expected to provide a clearer picture of future pricing.

A CFO survey by Towers Watson finds 75% of respondents think commercial property insurance prices have bottomed or are starting to increase.

The report surveyed 38 companies representing 20% of the US commercial insurance market.

The survey also finds that companies which use predictive modelling are gaining greater price increases that those which don’t.