Two of the founding shareholders of Bermuda-based Aspen Insurance Holdings Limited are selling up all their shares — just under eight million, which represents 10 percent of the company's total ordinary shares — worth around $227 million.

Aspen will not receive any proceeds from the sale of the shares by multi-billion dollar Blackstone Group and Credit Suisse private equity investment affiliate DLJ Merchant Banking Partners.

Blackstone Group secured a $4.75 billion initial public offering last week. During 2006 it made various financial deals around the world that involved an estimated total of $370bn.

It has been scaling down its share-holding in Aspen, which at the start of this year was around 12 million shares. Yesterday it was announced it would sell its final 5,707,625 ordinary shares.

At the same time DLJ is to sell its remaining 2,219,668 ordinary shares in an underwritten public offering.

Both companies will have no Aspen shares left once the sales are complete.

In a statement it was announced that Credit Suisse is acting as the sole book-running manager for the offering.

Credit Suisse proposes to offer Aspen's ordinary shares from time to time for sale in one or more transactions on the NYSE, in the over-the-counter market, through negotiated transactions or otherwise at market prices prevailing at the time of sale, at prices related to prevailing market prices or at negotiated prices.

Chris O'Kane, Aspen's chief executive officer said: "After five years, Blackstone and DLJMB, two of our founding shareholders, are selling their shares as part of their liquidity strategy. We want to thank them for their support in our establishment and growth since 2002."

Yesterday, Aspen shares were trading near their 52-week high and closed down 51 cents at $28.19.