MetLife (MET), the largest U.S. life insurer, plans to separate a substantial portion of its U.S. retail business from the core company, saying on Tuesday that the “regulatory environment” helped drive its decision.

MetLife is considering various approaches for splitting off the retail business, including an initial public offering, a spinoff or a sale. The business sells life insurance and other financial products across the United States, generating at least one fifth of MetLife earnings.

The company’s shares rose 8% to $45.06 in after-market trading on Tuesday following the announcement.

MetLife is currently in a legal tangle over federal regulators designating it a “systemically important financial institution,” or SIFI, in 2014.

That label, created after the massive financial crisis that started in 2007, means regulators deem the company too big to fail and triggers a requirement for MetLife to hold higher levels of capital.

Last January, the insurer asked a U.S. District Court to throw out the designation.

MetLife’s Chief Executive Steven Kandarian said in a statement on Tuesday the lagging retail section “risks higher capital requirements that could put it at a significant competitive disadvantage.”

“Even though we are appealing our SIFI designation in court and do not believe any part of MetLife is systemic, this risk of increased capital requirements contributed to our decision,” he added. “An independent company would benefit from greater focus, more flexibility in products and operations, and a reduced capital and compliance burden.”

Billionaire investor Carl Icahn is currently pressuring American International Group Plc., another insurer designated systemically important, to break itself up for many of the same reasons.

MetLife said that if made an initial public offering for the separate company, it would file a registration statement in approximately six months.

The new company, to be led by executive vice president Eric Steigerwalt, will not house certain parts of the U.S. retail segment, including the life insurance closed block and property-casualty units.

It would represent about 20% of Metlife’s operating earnings and have approximately $240 billion in total assets, based on September data, the company said.

Growth in MetLife’s U.S. retail business has been slowing, with the unit reporting an operating income of $523 million in the third quarter, down 33% from a year earlier. In the second quarter, retail’s operating earnings growth slowed to 2% from 12% a year earlier.

The company’s shares fell about 11% in 2015.