Portsmouth-based broker Time to Insure, which has 20 offices in the UK, has gone into receivership after suffering a cash flow problem.
The broker, which employs 100 staff, deals with more than 30 insurers and has about 30,000 policyholders.
"The company failed because it over-extended too quickly and became drained of working capital," said Duncan Swift of Grant Thornton, the receiver.
"I envisage that redundancies and branch closures will be necessary, but we are seeking to minimise these and are optimistic of achieving a going concern sale."
"The core of the business remains profitable and the value of the premiums are in excess of £10 million. We are confident it can be sold to a buyer who will continue to keep the business operating."