Staff at a City insurance broker are set to share in a multi-million-pound windfall as the company prepares to float on the stock market.

Cooper Gay, one of the world’s biggest privately owned insurance and reinsurance brokers, has appointed UBS, the Swiss banking giant, to prepare the company for a listing that could value the company at up to £250m.

The move, which is expected either at the end of this year, or in early 2010, could mean a shareout of as much as £170m for 160 employees who together own about 70% of the company’s shares.

Toby Esser, the chief executive, can look forward to the best windfall as he owns the biggest stake.

The other 30% is owned by Portuguese investment giant Sonae, which has helped to fund the company’s ambitious expansion through several cash injections.

The business was founded by David Gay and the late Derek Cooper in 1965. Gay will miss out on the bumper pay day because he sold his shares back to the company when he retired as a non-executive director in 2005.

Cooper Gay has been one of Britain’s fastest-growing companies, with profits rising at 40% a year at some stages as it expanded into numerous exotic locations around the globe — from the Bahamas to Peru, New York and Mexico — often through acquisition.

The firm has more than 500 employees worldwide and offices in almost 20 countries. It offers all forms of insurance, but has built up a reputation for specialising in marine services — it owns the yachting insurance specialist James Steele.

The business recently announced a 22% increase in income and a 15% rise in earnings for 2008.

The company recently beefed up its board ahead of the planned float with the appointment of Keith Harris, the football dealmaker and executive chairman of investment bank Seymour Pierce, as a non-executive director, as well as John Whiter, the former financial director of reinsurer Benfield, taken over last year by US insurance giant Aon for £840m.

Meanwhile, an investment company set up to back solar energy projects is planning to float on the Alternative Investment Market this month.

Solar Opportunities, a vehicle established to invest in both start-up and existing solar power installations in Spain, has hired Panmure Gordon, the stockbroker, to work on the share offering.

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