US commercial and personal lines rates grew last month, with some lines showing significant increases, according to US insurance exchange MarketScout.

Property and casualty rates increased 5%, compared with 4% the previous month.

Commercial property, excess liability, general liability and workers’ compensation rose 5%.

In terms of industry class, manufacturing rates jumped to 6%, compared with 4% the previous month.

“The manufacturing rate increase was surprising,” MarketScout CEO Richard Kerr said.

“Normally, manufacturing is a very stable industry class, absent from quick pricing changes. Going from 4% to 6% was unusual.”

Personal lines increased to 4%, with homes worth more than $US1 million ($950,000) significantly affected by Hurricane Sandy and weather-related events.

“Rates moved up from 2% in October to 5% in November,” Mr Kerr said. “That is the largest month-on-month rate increase we have seen in the 11 years we have been tracking rates in the US.

“It appears insurers of high-value homes are adjusting rates upward to account for increased exposure to weather-related events.”