Strong growth overseas helped the internet fashion retailer ASOS maintain its upward momentum in the fourth quarter.The firm, which sells clothes inspired by trendy celebrities (the name stands for 'As Seen on Screen') saw year-on-year sales growth of 70% during the quarter, with UK's revenues up 24% to £44.9m and the international division's soaring by 161% to £48.4m."With International becoming an increasingly significant part of our future, I was pleased to see our International sales mix exceed that of the UK for the first time, accounting for 52% of our retail sales," said chief executive Nick Robertson. "Profit before tax, pre exceptional, for the full year to March 2011 is likely to be towards the top end of expectations."The EU remains ASOS's main overseas market, but it was sales to the US and other countries that were the main drivers. EU sales rose by 77% to £21.3m, US sales were up by 222% to £7.1m and rest of the world sales rose an eye-watering 367% to £20m.