Asos boss unfazed by slowing UK sales growth as international revenues soar

His comments came as the online fashion retailer's interim results revealed a 36pc fall in pre-tax profits, due to one-off costs of moving to a new warehouse in Barnsley.

Asos shares took a dive last month when the company revealed a significant slow-down in UK sales growth, at just 1pc in the second quarter. This brought domestic growth for the first half down to 8pc, compared with 26pc for the first half last year.

The company nevertheless saw total retail sales growth for the first half of 60pc, at £211m, on the back of impressive international sales growth of 150pc.

Mr Robertson said the UK remained "challenging" and he expected domestic sales growth would remain "somewhere between flat and low single digit" over coming months as rival retailers continued to offer heavy discounts.

He said he would still "pull some levers" to keep Asos's UK business going, but he did not have to "go with the flow and promote and discount in the way that everybody else is" when he could instead sell the same item to someone abroad for greater profit.

"I have one warehouse and one dress," he said. "That dress is sat in Barnsley. If I sell that dress in Aberdeen or Adelaide it makes no difference to me. The difference is that if I sell it in Adelaide I make more money."

Despite higher transportation costs, sales in Australia were 30-40pc more profitable, due to exchange rates, the fact he did not have to pay VAT on those sales, and Australian consumers being "less promotionally driven".

Asos reported a retail gross margin for the first half of 49.1pc. Mr Robertson said: "Our retail margin has gone up and our retail margin in H2 is going to go up even more."

Sales outside the UK already account for 58pc of total and Mr Robertson expects this figure to be more than 90pc by 2015/16.

Asos has websites in the United States, France, Germany, Australia, Spain and Italy and is planning expansion into China within the next two years once it develops its website platform to handle different language characters.

Despite slowing domestic growth, Mr Robertson was adamant that Asos had "categorically not" hit saturation point in the UK market, with two million registered customers compared with six million 16-34-year-olds shopping online, and brand awareness lower than it could be.

He said: "I spent less in marketing in the UK in H2 than I did last year. I could turn a lever and drive it and make it happen but I would rather turn a lever internationally because that's considerably more profitable for me."

Pre-tax profits in the six months to September 30 were £4.49m but, excluding the £7.2m exceptional costs of the warehouse move, were up 66pc at £11.7m. Total group revenues were £217.3m, up 56pc.

Shares in Asos fell 62p or 4.1pc in early trading but by lunchtime had recovered slightly and were down 17p, or 1.13pc, at £14.83. Asos shares peaked at £25 in June.