The composite rate for US commercial insurance during May was up 4%, according to insurance exchange MarketScout.

“Workers’ compensation and commercial property rates continue to lead rate increases across the US at 5%,” CEO Richard Kerr said.

“Business-owners’ policies had the next greatest rate increase at 4% together with small and medium account rates.”

Large accounts during May were up only 3% while “jumbo” accounts grew 1%.

“It’s not unusual for underwriters to price jumbo accounts aggressively because of the cachet they bring,” Mr Kerr said.

“It is difficult to compare rates with smaller accounts because jumbo accounts frequently implement high retentions, captive involvement and heavy reinsurance.”

He says insurers value a Fortune 100 company account higher than smaller accounts because of the lower loss ratios, but that may not make economic sense.

“A few major commercial insurers are extremely aggressive when pricing jumbo accounts,” Mr Kerr said.

“Those insurers are suffering from the ‘show pony syndrome’ as inadequate pricing on prior years is coming home to roost.”

MarketScout predicts pricing on these account will increase.

Rate increases for US personal lines during May rose 2%, he says.

“As the wind season approaches, rates in coastal areas are increasing, with many insurers pulling back,” Mr Kerr said. “Many of the new quotes do not include as much coverage and implement higher deductibles.”