Online fashion retailer Asos.com continued its rapid ascent last year by managing to substantially increase its sales, margins and profits across its operations.

Full-year results for the period ending March 31st 2012, published today, show retail sales grew 49 per cent, gross margins improved by 180 base points and profit before tax was up 43 per cent year-on-year to total £40.3 million.

As reported in a previous trading update, retail sales in the UK have slowed considerably as its presence in its domestic market matures, but the group have still managed to profit from tremendous international growth – with non-UK sales up 103 per cent compared with the previous year.

CEO of Asos Nick Robertson described the performance as “strong”, and said that the business was well on the way to becoming “the world‘s number one online fashion destination”.

Simon Chinn, Lead Consultant at analyst firm Conlumino, hailed the launch of country-specific websites in Italy, Spain and Australia as essential to the group‘s international success.

“Over the last few years ASOS has proactively embarked on building up its presence in growing online fashion markets across the globe, which has significantly helped ASOS diversify its business away from its home market in the UK, where it is already well established and reaching maturity,” Chinn said.

International sales represented 59 per cent of total trading during the year, and during the final quarter this share increased to 62 per cent.

Asos also opened a new warehouse in Barnsley during the year which it says has improved efficiency, and introduced innovations such as augmented reality into its online magazine.

Chinn continued: “Another area that bodes well for ASOS is that its own label is becoming a more established global fashion brand.

“While third party brands still remain an important part of its business, ASOS‘s own label adds a degree of exclusivity to its product offering, driving customers to its site to seek out the latest ASOS trends.

“Sales of its own label now account for 55 per cent of total sales. This is likely to grow further as demand for the ASOS brand is even higher internationally.”