US commercial insurance rates increased by an average of 1.5% last month, according to analyst MarketScout.

Small accounts of up to $US25,000 ($28,282) were up 3%, while “jumbo” accounts of more than $US1 million ($1.13 million) were flat.

Contractors paid the highest rate rise at 4%, followed by transportation at 3%.

“We are measuring changes with a high degree of sensitivity because the monthly changes are ever so slight,” MarketScout CEO Richard Kerr said.

“However, rates clearly continue to drift downward.”

Personal lines were also up last month, with home rates rising 4% for properties worth less than $US1 million and 3% for properties of more than $US1 million.

Motor rates were up 2% and personal contents coverage was up 1%.