Jardine Lloyd Thompson Group Plc’s Dominic Burke said the worst slump in prices for insurance policies since Sept. 11, 2001 has led some insurers to take on too much risk to win business.

Burke, the chief executive officer of the U.K.’s biggest publicly traded insurance broker, said that some companies were accepting a return on capital of as low as 5-6 percent to increase growth. That compares with a normal average of 12-13 percent.

“If capital becomes either ill-disciplined or naive, then it won’t be long before they lose their shirts,” Burke said in a telephone interview from London. “Underwriters are targeting or accepting lower-return capital, and one has to question whether it properly reflects” their risks.

Insurance rates have fallen amid fewer catastrophes and as record low interest rates prompt pension funds and other investors to compete with traditional insurers to provide capital to generate yield. Burke said rates have dropped as much as 30 percent in some lines of business, while renewals in reinsurance were one-sixth of what they were.

“This is not just part of the ordinary insurance cycle,” he said. “The sharp declines in rates accelerated through May and June and into July. Colleagues around the world are saying this is unique.”

JLT’s stock fell 2.5 percent to 1,030 pence at noon in London trading as the company said in a statement that it was more “cautious” for the remainder of the year because of insurance rates and the continued strength of the pound.

The company on Tuesday reported a 16 percent gain in pretax profit to 98.4 million pounds ($166.8 million) for the first half of the year and increased its dividend 5 percent to 10.6 pence a share.