The CEO of ASOS has hailed a year of "substantial progress" as the online fashion giant ramped up its investment in technology and grew annual revenues to almost £2.5 billion.

The company, which employs approximately 4,400 people, posted group revenue of £2.42 billion for the financial year to 31 August 2018.

This was an increase of 26 per cent from £1.92 billion a year earlier.

Profits before tax soared by 28 per cent to £102 million after what ASOS described as a “record year of investment”.

The London Stock Exchange-listed group said its tech capability continues to go from strength to strength, demonstrated by the 2,900 tech releases during the year compared with 1,300 in the previous period.

"This has been another year of substantial progress for ASOS," said CEO Nick Beighton, who emphasised that the company’s profit was increased despite its record levels of investment.

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He added: "ASOS is moving fast and is as differentiated as ever.

"The potential for our business is huge and we remain focussed on building ASOS into the world's number one destination for fashion loving twentysomethings."

ASOS revealed that improvements across tech during the year included new sites, new languages and improved recommendations algorithms. It also extended visual search (Style match) to international customers and delivered improved personalisation on homepages.

The group said it also made its "first meaningful move" into artificial intelligence-driven conversational interfaces, but did not elaborate further.

ASOS also reported a significant increase in active customers, ending the financial year with 18.4 million, up 19 per cent compared to last year. This growth was largely driven by engaging content and investments in the technology platform.

ASOS is headquartered in Camden (North London) and its customer care site is in Leavesden, near Watford, where it recently agreed a major deal for an additional 125,000 sq ft.

The group also has smaller teams in Birmingham, Barnsley, Paris, Berlin, New York and Atlanta.

The online fashion retailer is still on the look-out for a new CFO but said the search is "progressing well" and it would hope to make an announcement shortly.