Private equity firm Apollo-owned Aspen Insurance on Wednesday filed its paperwork for an initial public offering in the United States, according to a regulatory filing.

The company did not disclose details about the size of the offering, but is reportedly targeting a $4 billion valuation. It also did not provide details about the exchange where it plans to list its shares.

Aspen went private in 2019, after funds affiliated to Apollo Global Management agreed to buy it in an all-cash deal valued at $2.6 billion.

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The listing will test investor appetite for the sector, which was strong in the first half of the year but has tempered down in recent market debuts.

Shares of Fidelis Insurance and Hamilton Insurance are trading below their IPO price after their market debuts.

For the nine months ended Sept. 30, Aspen reported a net income of $305.2 million, compared with a loss of $112.8 million a year earlier.

In the same period, net written premiums came in at $1.98 billion, compared with $2.29 billion a year earlier.

The Bermuda-headquartered company founded in 2002 underwrites specialty insurance and reinsurance on a global basis through its wholly owned subsidiaries.

Goldman Sachs and Citigroup are the lead underwriters for the offering.

(Reporting by Arasu Kannagi Basil and Jaiveer Shekhawat in Bengaluru; editing by Shounak Dasgupta)