Petershill Partners, which takes minority stakes in alternative assets managers including private equity, venture capital and hedge funds, expects to achieve a free float of 25% before any greenshoe option, making it eligible to join the FTSE indices.

Hoping to cash in on a boom in private equity funds, the deal will consist of a sale new ordinary shares and existing shares to raise between $1.3 billion and $1.5 billion, pre-greenshoe, to fund ongoing expenses and acquisitions.

The shares are expected to be priced on Sept. 28 and start unconditional trading Oct. 1, the bookrunners said.

Private equity funds have soared in value over the past year as money pours in from investors looking for higher returns when interest rates are so low.

Bank of America, Goldman Sachs, and JPMorgan are global co-ordinators on the deal while BNP Paribas and UBS are acting as bookrunners.

(Reporting by Kirstin RidleyEditing by Rachel Armstrong)