A new wave of "silver surfer" older shoppers helped drive a strong Christmas for the N Brown home shopping group.

The owner of online lingerie store Figleaves and plus-size brand Simply Be said underlying sales rose 5.1% in the 19 weeks to 11 January as its House of Bath brand, aimed at the over-70s, enjoyed a 30% rise in sales.

"Our whole mature portfolio of brands is really seeing increased browsing and propensity to shop online from tablet computers," said chief executive Angela Spindler. "Older customers are now prepared to place an order using a tablet, which they typically weren't on a mobile phone. It's a real driver to online growth in that market," she said.

In all 45% of N Brown's online sales came from mobile devices including smartphones and tablet computers. More than half of the group's sales now come from the internet as shoppers switch from traditional catalogues.

Spindler, meanwhile is leading the expansion of N Brown's high street presence with plans to reach 25 outlets, up from seven at present.

N Brown also benefited from shoppers' increasing confidence in online retailer's ability to deliver close to Christmas and strong sales of party dresses and novelty Christmas jumpers. The retailer sold more than 2m Christmas-themed sweaters. Profit margins slipped slightly as N Brown was forced to compete with discounting across the high street but the retailer said it still expected to meet profit forecasts.