NEW YORK (Reuters) ? Reinsurer Aspen Insurance Holdings Ltd. yesterday raised its estimate of losses from Hurricanes Katrina, Rita and Wilma and said it would sell up to $200 million of new shares to increase its capital.

Bermuda-based Aspen said it now expects after-tax losses of between $470 million and $535 million from the hurricanes, compared with an earlier forecast of $325 million to $400 million.

The earlier forecast was prior to Hurricane Wilma in October, which Aspen expects to result in losses of between $20 million and $35 million.

The change in estimates also includes an increase of $27 million in the costs of Katrina and Rita, which struck the US Gulf Coast in August and September, and a charge of $46 million in relation to reinstatement premiums.

Aspen said there was no assurance that losses would stay within the new range.

The company said it would publicly sell up to $200 million worth of shares, while UK shareholder Wellington Underwriting Plc said it would sell up to 6 million shares, or about two-thirds of its 14 percent stake in Aspen.

The size and pricing of Wellington?s sale will depend on various factors including market conditions, with no assurance it will proceed. But Wellington said if completed, the proceeds would be used to support its underwriting operations at Lloyd?s of London.

Wellington last month raised its estimate of losses from this year?s US hurricanes, with analysts now expecting the insurer to post a loss for 2005.

Aspen said it has concurrently started a public offering of $200 million of perpetual preferred income equity replacement securities.

Lehman Brothers is acting as the sole book-running manager for both offerings. Aspen plans to use proceeds to contribute to the capital of its operating subsidiaries and for general corporate purposes.

In morning trading on the New York Stock Exchange, Aspen shares were down 76 cents, or 3 percent, at $24.25. They closed down 1.36 percent at $24.67.

Aspen shares are virtually unchanged from the start of the year, while the Standard & Poor?s Insurance Index has risen about 14 percent.

Wellington Underwriting shares were little changed at 94 pence.