UK fashion retailer Jigsaw has booked a double-digit increase in sales over the Christmas trading period despite "aggressive discounting on the high street".

The privately-owned company said like-for-like sales grew 17% during the five weeks to 28 December, while online sales jumped 39%.

The news came as Jigsaw revealed a 21% increase in full-year net profit to GBP1.9m (US$3.1m). Sales were up 7% to GBP64.2m during the 52 weeks to 28 September, while online sales jumped 36%. Net trading margin improved by 160 basis points.

Chief executive Peter Ruis said: "We are pleased with the progress we have made during this period. Trading conditions remain challenging but we are optimistic for the current financial year.

"The focus will be on continuing to bring innovation to our customers, in both bricks and clicks, enhanced by significant investment over the next 12 months."

In addition, the retailer said it will open a new flagship concept store in London in April, which Ruis said will "begin the journey to re-define Jigsaw for the next decade."