Assured Guaranty Ltd. said Tuesday it will sell 23.9 million shares in a public offering, with proceeds used for general corporate purposes.

The underwriter, UBS Securities LLC, has 30 days to buy up to an additional 3.5 million shares.

Assured Guaranty is a Bermuda-based holding company. Its subsidiaries provide credit enhancement products to the U.S. and international public finance, structured finance and mortgage markets.

Shares declined 79 cents, or 3.5 percent, to $21.89.