A U.S. investment bank and a British private equity firm have agreed to pay $1.8 billion for Hub International Ltd., a large insurance broker.

Hub, Chicago, sells life insurance, health insurance and employee benefits as well as property-casualty insurance.

The would-be acquirers are private equity funds advised by a unit of Apax Partners L.P., London, and an investment company affiliated with Morgan Stanley & Company Inc., New York.

The announced price is 28% higher than the 90 trading day average Hub closing stock price, Hub says.

Hub has a right to find an alternative buyer and walk away from the deal if it pays a $21 million break-up fee, the company says.