Swiss Re is pressing ahead with a flotation of British subsidiary ReAssure on the London Stock Exchange, the world's second largest reinsurer said today.
The business has been valued by analysts at around £3.5 billion.
ReAssure, Britain's sixth largest life insurer, plans to list at least a 25% stake, it said in a statement.
The insurer has £68.7 billion of assets under administration and focuses on so-called closed book policies that are shut to new customers.
Under the flotation plans, Swiss Re would cut its stake to below 50% from 75% at present.
Japan's MS&AD Insurance Group Holdings intends to keep its holding at 25% after the initial public offering (IPO).
Swiss Re wants ReAssure to have access to new capital to acquire additional closed books of policies, which are paying out to existing members but are no longer being actively sold.
Scale is increasingly important in an industry where insurers are struggling to pay guaranteed returns for life insurance policies due to record-low interest rates.
Swiss Re, which said in August it was examining a possible flotation of ReAssure, has not said what it plans to do with the money it raises from the IPO, nor when it might tale place.
ReAssure's publication of the registration document for the IPO will be the first step towards a listing, Swiss Re said.
ReAssure's chief executive Mark Hodge said he saw growth opportunities through further consolidation of closed life and pension books in the UK.
"A potential IPO would provide us with additional flexibility to take advantage of the opportunities we see," he said.
The CEO told reporters ReAssure would pay £265m in dividends to investors over a five-year period.
Swiss Re said it and MS&AD would inject £481m in new capital into ReAssure ahead of the IPO.
