Asos has delivered “ another strong” performance for the year ending March 31 as profit before tax including exceptionals rocketed 93% to £30m, as it reveals chairman Lord Waheed Alli prepares to step down from the business.

The fashion etailer delivered a profit before tax and exceptionals increase by 43% to £40.9m and group revenue soared 46% to £495m. Exceptional costs are related to the opening of the new warehouse in Barnsley.

Total retail sales increased 49% to £481m as UK retail sales grew a “solid” 7% to £197m against International retail sales – the “key driver” for retail sales - which continue to surge, up 103% to £283m.

Asos improved its retail gross margin by 290bps in the year and gross margin improved by 180bps to 50.9% against  29.1% last year.

In the year the etailer launched three new country websites in Australia, Spain and Italy  and located its first overseas marketing office in Australia. Further overseas offices are planned for the new financial year in countries where Asos has a website.

Alli will depart from his role after 12 years at the business. He will step down once his replacement has been identified.

Chief executive Nick Robertson said: “We completed the year with further penetration into existing international markets and substantial expansion into new territories. Additionally our successful transition to a new 530,000 sq ft warehouse in Barnsley became fully operational in June 2011.

 “We remain positive in our outlook for 2012/13 as we continue our journey to becoming the world’s number one online fashion destination. Our International roll out continues and our ambitions for the company are in sight.”

Asos said it is “committed” to its £1bn sales target from five major markets by 2015, as its International markets are now “firmly established”.

According to the retailer it is the second most visited apparel site on the planet  on a daily basis  for 15-34 year olds and at the time of reporting 69% of the website’s traffic was derived outside of the UK against 58% a year ago. Asos now has now has as many international customers as it does in the UK. It said “there is still significant opportunity within the gloabl twenty-something market”.

On product the retailer said its own label Asos brand had has been key in allowing the etailer to offer unique products and makes up 55% of total sales. Menswear has also seen an uplift, increasing 60% across the year as fashion is just as important to men as their female counterparts, Asos said.