NEW YORK (Bloomberg) — American International Group, the insurer being pressured by activist investor Carl Icahn to shrink the company, plans to pursue a partial spin-off of its mortgage-guaranty unit, according to a person familiar with the matter.

AIG intends to maintain a significant stake in the business, said the person, who asked not to be identified discussing a plan that hasn’t been publicly announced. A partial spin-off could allow AIG to maintain some of the tax assets associated with the United Guaranty business, the person said.

The insurer has scheduled a presentation for tomorrow to discuss chief executive officer Peter Hancock’s vision for boosting returns and narrowing the company’s focus.

Icahn has demanded a drastic reshaping of the insurer, whose biggest units offer property-casualty coverage and life policies. Jennifer Hendricks Sullivan, a spokeswoman for New York-based AIG, declined to comment on the plan, which was reported earlier on Friday by Reuters.

Mortgage insurers cover losses for lenders when homeowners default and foreclosure fails to recoup costs. Publicly traded mortgage guarantors MGIC Investment Corp and Radian Group Inc have plunged in New York trading this year, which could reduce the amount that AIG would be able to get through a sale, John Nadel, an analyst with Piper Jaffray Cos, said on Friday in a note to clients.

The unit is worth $3 billion to $3.5 billion, he said, lowering the range from his previous estimate of $3.5 billion to $4.8 billion.