Royal London reported a "challenging" market led to its life and pensions sales dropping slightly in the first half of 2018.
Sales in life and pensions went down by £1m to £6.077bn overall in the first six months of the year.
Royal London has attributed this to the end of the automatic enrolment roll-out and "sluggish" economic growth, but it has said these were offset by increases in personal pension and life assurance new business sales.
The mutual's profits before tax increased by £31m to £358m.
Phil Loney, chief executive of Royal London, said: "Sluggish economic growth and the ending of the auto enrolment roll out provided a challenging backdrop for pensions and investment companies in the first half of 2018.
"I'm pleased to report that Royal London has consolidated its record 2017 trading position with EEV pre-tax profit up 9 per cent to £358m, reflecting an operating profit of £187m in the first six months of the year."
Individual pensions and drawdown new business sales were up 23 per cent to £3.5bn while intermediary UK protection new business sales increased by 14 per cent to £383m.
The company reported gaining 86,000 new entrants to its group pension schemes over the first half of 2018.
Meanwhile Royal London Asseet Management saw its funds under management increase from £114bn to £117bn.
Royal London Platform Services, which supports a number of platforms including Ascentric and Succession Investment Platform, saw net flows remain stable at £612m, with assets increasing by 5 per cent to £15.1bn.
In the first half of 2018 Royal London migrated the first phase of Ascentric advisers to its new platform solution, Sonata.