Just's sales were up 41 per cent in the first quarter of 2018.
The retirement income provider's total new business sales for the first three months of 2017 were £617m, compared with £436m in the same period last year.
The increase in sales was driven by growth in Just's defined benefit (DB) de-risking business, where sales almost doubled from £125m last year to £249m in the first quarter of 2018.
Other parts of the business also grew, but at a slower rate. Sales of care plans were up 2 per cent to £17m and sales of guaranteed income for life products were up 8 per cent to £188m.
In the first quarter Just advanced £151m in lifetime mortgage loans, up 42 per cent from the same period last year.
Rodney Cook, chief executive of Just, said: "We have taken full advantage of buoyant market conditions to make a strong start to the year, especially in DB. We have maintained our financial discipline and are in a position to price even more selectively over the balance of the year.
"The pipeline remains strong across our main products, particularly in DB de-risking, and we look forward to the remainder of the year."
Mr Cook said the opportunities for DB de-risking were increasing as employee benefit consultants were proactively managing the industry pipeline and the market was becoming less seasonal.
Just's protection sales fell by 50 per cent, from £2m to £1m and its sales of drawdown fell by 2 per cent, to £11m.
The company was formed by the merger of Just Retirement Group and Partnership Assurance in August 2015 and rebranded as Just in early 2017.