LONDON (Reuters) ? Bermuda-based reinsurer Alea Group Holdings arrived as the London market's fourth biggest flotation of the year on Friday, with a market value of just over 450 million ($760 million).

Alea raised 165 million from the sale of shares at 250 pence apiece, at the lower end of expectations. A spokesman said the initial public offering was four times subscribed.

Alea joins a growing list of companies willing to brave a float as the stock market revives after a three-year slump. The only bigger companies to list in London this year have been publisher Yell, another reinsurer Benfield and Northumbrian Water on the junior market AIM.

Alea, formed in 1997 but under new management for the last four years, offers a range of property and casualty reinsurance.

Reinsurers, who assume risks that are too large or volatile for insurers to take on their own balance sheet, have enjoyed hefty price increases since the World Trade Center disaster in 2001 sent demand for property and aviation insurance soaring.

"There probably will be upside to reinsurer shares generally as good results come through, but it is the peak of the premium cycle so valuation-wise, I think people are a bit nervous about reinsurers in the medium-term," said Chris Hitchings, an analyst with Commerzbank.

Dennis Purkiss, Alea's chief executive, said he expected improvement in rates to continue for at least the next year and he was comfortable with growth expectations for 2004.

Alea said net proceeds from the offer of 151 million would be used to fund future growth.

"We intend to leverage the enlarged capital base immediately by growing existing renewal business and capturing new business that is expected to generate attractive returns," Purkiss said on a conference call.

Alea sold 66 million new shares in the IPO, representing 38.2 percent of its enlarged share capital. A further 9.9 million shares could be issued under an over-allotment option.

US private equity group Kohlberg, Kravis Roberts saw its majority stake of 60 percent diluted to 39.4 percent by the offer. KKR has agreed not to sell shares for six months.

Management will hold an eight percent stake ? worth about 36 million ? and will not sell shares for a year.

Several US state pension funds are also major stakeholders, notably Wisconsin, California and New York states.

Goldman Sachs and Merrill Lynch are bookrunners on the deal.