Better conversion of internet traffic has led to a 24% increase in UK sales for online fashion retailer Asos, but it's the US sales which are driving the brand's revenue.

One of the British pioneers for online shopping, Asos has also seen strong growth in its overseas markets, with European sales increasing by 15% compared to the same quarter in 2011.

US sales are also doing well, according to Nick Hood, business analyst for Company Watch.

He told Huff Post UK: "Having two thirds of its sales outside the UK is wise positioning in such hard times for discretionary spending in Britain. ASOS has the benefit of a healthy financial base to continue its development and expand further overseas.

"We calculate health scores based on published accounts. In this case, the overall picture shows a very creditable rating of 78 out of a possible 100, confirming that it has the necessary resources to support the continuous investment in marketing and technology that its trading platform demands."

Chief executive of Asos Nick Robertson said in its statement to the market on Tuesday that its international business had grown in total by more than 34% and now accounts for 63% of its total retail sales.

"We achieved more than 57% growth in the US, more than 42% growth in rest of the world, and 15% growth within the EU. Once again the performance of countries where we have dedicated websites was significantly better than the EU performance as a whole," he added.

ASOS currently offers more than 60,000 branded and own label product lines across womenswear, menswear, footwear, accessories, jewellery and beauty, with approximately 1,500 new product lines being introduced each week.

The site attracts 23 million unique visitors a month, up from 18.2m in November 2011, and boasts 10.1m registered users and 5.4m active customers from 160 countries.