Pre-tax profit at Saga dropped by £60m in the six months to 31 July 2014 with IPO costs totalling £50.8m.
The over 50s insurer floated on the London Stock Exchange in May.
Group profit before tax on a like-for-like basis increased 14.9% to £106.5m for the six months ended 31 July 2014 (H1 2013: £92.7m).
However, profit before tax, after IPO expenses and a one-off cost of new debt, dropped by £60m from £92.1m in the first half of 2013 to £32.8m for the same period in 2014.
IPO costs totalled £50.8m while £4.3m was spent on restructuring and other activities.
The insurer reported a 15.2% increase in operating profit to £110m (H1 2013: £95.5m).
Group trading Ebitda also increased, by 9.7%, to £130.4m from £118.9m for the same period in 2013.
Chief executive Lance Batchelor said the company had made a positive start as a listed company and was on track to meet market expectations for the full year.
"We will continue to work hard to capitalise on our insight and structural advantages to ensure the Saga offer is increasingly beneficial to our customers and delivers returns for our shareholders," Batchelor said.
The over-50s insurer also announced the appointment of Jonathan Hill as group chief financial officer. Hill is to take over from Stuart Howard who he retires at the end of 2015.
The group reported its health insurance and travel insurance results together. This segment saw a 1.7% increase in revenue to £49m. Gross written premiums rose 8% from £58.4m in the first half of 2013 to £63.1m in 2014.
Reserves releases totalled £29.8m, a marginal drop in the 2013 result of £33m.
Alongside its results, the insurer announced two new opportunities. It said it intends to enter the wealth management services sector and is currently in talks with several providers to find a partner to enter the market.
It has also partnered with retirement village developer Rangeford to enter that market. Saga will initially provide sales and marketing advice on the development of Wadswick Green village in Wiltshire.
