Online fashion retailer ASOS revealed an impressive 45 per cent increase in total year-on-year quarterly retail sales and expects full year results to be in line company expectations.Total retail sales surged to £194m for the three months to May 31st 2013 from £134m for the same period a year earlier. Total group revenues also jumped to £197m from £138m before.ASOS, which recently agreed to a trial tie-up with high street chain Primark, said UK sales grew by 39% to £64.3m. Sales at its International business, which now accounts for 67% of its total retail sales, accelerated by 48%.US retail sales bounced 59% during the three month period, EU sales increased 56% while Rest of World retail sales climbed 38%."We continue to see stronger growth in those countries where we have dedicated websites and in-country teams, notably in the US, France, Germany and Australia. Our dedicated Russian website launched on May 2013 1st," ASOS said in its trading update.CEO Nick Robertson commented: "Retail gross margin grew by 10bps over the quarter as we annualised last year's price investments. We anticipate a further increase in the fourth quarter which should result in a small improvement for the year as a whole.""We remain positive in our outlook for the year to August 31st 2013 and expect our full year results to be in line with expectations."