The UK company, which has been majority-owned by Cinven since 2008, would be valued at between £1.3bn and £1.6bn at that range according to Reuters, which cited two people familiar with the matter.
It said the firm plans to raise about £125m through the sale of new shares to help it pay down existing debt.
Cinven plans to sell at least a quarter of its shares in the business through the IPO, which Reuters previously reported could be completed by the end of the month.
Last year Partnership posted profits of £112m, up 56 per cent from 2011.
Chairman of Partnership Chris Gibson-Smith said, “The IPO is a natural step for Partnership, and the profile generated in the public markets will support its continued growth as the population ages and the potential demand for secure retirement income grows substantially.”
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