Ironshore Inc., the insurer led by executives who left American International Group Inc. in the financial crisis, filed for a $100 million initial public offering so that its backers can reduce their stakes.

Bank of America Corp. and UBS AG are managing the offering, Bermuda-based Ironshore said Tuesday in a regulatory filing. The $100 million figure is a placeholder used to calculate registration fees and could change.

Ironshore said that shareholders’ equity stood at $1.81 billion as of March 31. The insurer posted net income of $97.4 million last year, down from $131.7 million in 2012. Chief Executive Officer Kevin Kelley and President Shaun Kelly joined the property/casualty insurer from AIG in 2008.

“The financial crisis of 2008, which had a material negative impact on several leading U.S. P/C insurers, created a unique opportunity for Ironshore to accelerate its hiring and growth strategy,” the company said in the filing.

Ironshore was founded in December 2006 with more than $1 billion in private-equity backing. Irving Place Capital Management LP owns about 24 percent of Ironshore and Calera Capital Advisors LP has 19 percent, the filing shows.