The company is also moving into menswear, household and electrical products to appeal to customers in their 30s and 40s.
N Brown's traditional customer base is women in their 40s and 50s but this market offers limited scope for growth.
Jim Martin, N Brown's chief executive, admits that younger shoppers are a greater credit risk. The move will also bring the company into more direct competition with the mainstream catalogue shopping groups.
The strategy appears to be working. N Brown yesterday sidestepped problems suffered by high street rivals to anounce pre-tax profits up 16.6 per cent to £26.5m for the year to February. Sales also increased by more than 11 per cent to £208m.
N Brown has been adding new catalogues to its main titles such as JD Williams. Recent launches such as Fashion World, Candid and Classic Combinations now account for £25m sales a year.
Classic Combinations was launched last year after extensive research into the shape of the modern woman. More than 50,000 measurements were taken from 700 women over a three-year period. The company says customers have responded well, with the catalogue achieving sales of £4.8m in its first year, and better than expected losses of £100,000. The catalogue is expected to make a profit next year.
The tactic of sending out mini-catalogues and leaflets with the monthly bills has proved successful and these brochures now account for 40 per cent of sales.
Mr Martin said the company was on the look-out for acquisitions though no announcement was imminent. In November, N Brown paid £4.7m for the Sander & Kay menswear mail order business.
Mr Martin said he expected trading conditions to remain tough but was confident the company would continue to perform well. The dividend was raised by 20 per cent to 4.8p. The shares finished a penny lower at 234p.