Shares in Just Retirement have been priced at 225p each ahead of its initial public offering (IPO), based on a market capitalisation of £1.1bn.
Shares in the private equity backed enhanced annuity specialist will begin trading today under the ticker 'JRG'. Gross proceeds from the sale are expected to be in the region of £343m.
Just Retirement chief executive officer Rodney Cook said investors had responded positively to the strength of "our differentiated business model and proprietary intellectual property".
"We look forward to executing our growth strategy as a listed company and bringing increasing value to our customers and shareholders as we introduce further innovation into the retirement income market," he added.
Chairman Tom Cross Brown said: "Our listing on the London Stock Exchange is an important milestone for the business and we look forward to welcoming our new shareholders as we enter the next phase of our growth strategy."
Paul Bruns and Elaine Parkes
3,000 left to transfer
Record numbers of people aged 90 plus
From 3 to 10 October