Online fashion and beauty store ASOS continued its recent barnstorming performance, boosting revenues by a third in the last quarter.Group revenues were up 31% to £145.2m in the fourth quarter, the firm said in a trading update.Retail sales were up 31% year-on-year, with a 15% rise in the UK and a 42% jump in international trading.International sales now make up 65% of the company's total business, it said.Retail sales for the full year to the end of August increased 38% to £538m.ASOS' retail gross margin was up 70bps on prior year, while the number of active customers on its site rose by almost a third to 5m by the end of August."Profit for the five months ended August 31 and pro forma full year, are expected to be in line with expectations, and we approach our new financial year with continued confidence," said Chief Executive Nick Robertson.