UPDATE 1-ASOS says international sales help to shore up demand

* Sales growth to be maintained in current year

* Company expects resilient UK clothing market

* Shares fall 7.5 percent after hitting 2-1/2 year highs (Adds CEO comment, analyst comment, share price)

By Sarah Young

LONDON, Oct 18 (Reuters) - ASOS, the British onlinefashion retailer, said fast-changing product ranges and anexpanding international customer base would help it to maintainsales growth and defy tough conditions in the UK clothingmarket.

Britain's more established clothing retailers including Next and Marks & Spencer are struggling to growsales, with data from market researcher Kantar Worldpanelshowing the British fashion market witnessed its steepestdecline since 2009.

ASOS, however, forecast sales growth of up to 25 percent forthe 12 months to August 2017, building on the 26 percent jump itreported on Tuesday for 2015-16.

"I'm expecting the major growth to come from internationalbut I'm not expecting UK to fall away substantially," ChiefExecutive Nick Beighton told reporters on a call.

Shares in ASOS, founded in 2000 for fashion-conscioustwentysomethings, traded down 7.5 percent to 4,925 pence, havingbeen on a strong run going into the results -- they hit theirhighest level for two and half years on Monday.

More than half of the online retailer's sales come frominternational markets, giving it an advantage over UK-focusedshops given the devaluation of the pound since Britain voted toleave the European Union on June 23.

But despite concerns over consumer confidence due toeconomic uncertainty since the vote, the CEO said he expectedBritish consumers to keep buying.

"I think we'll see another strong performance from the UK,"he said.

ASOS's rapid range changes, it adds over 4,000 new styles aweek to its website, and its strong social media presence, will help it continue to grow, said Beighton.

ASOS has faced criticism from unions and media over workingconditions at its main warehouse in northern England, but theretailer called the commentary inaccurate and misleading in itsearnings statement.

ASOS posted underlying pretax profit of 63.7 million poundsfor the year to August 31, ahead of analysts' average forecastof 62 million, and a 37 percent jump on the previous year.

Profit was boosted by the weakening of sterling versus theU.S. dollar and euro in the wake of Britain's vote to leave theEuropean Union. (Reporting by Sarah Young; Editing by Keith Weir)