UPDATE 1-Europe's warm autumn slows sales growth at Zara-owner Inditex

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MADRID, Dec 13 (Reuters) - Inditex, the world's biggest clothes retailer and owner of Zara stores, reported a slowdown in sales growth in its third quarter on Wednesday as Europe's warm autumn kept shoppers away, although analysts pointed to a brighter end of the year.

Fashion retailers such as Next and John Lewis have already reported a hit from warmer-than-usual weather as shoppers passed on new winter ranges. Inditex's biggest rival, Sweden's H&M , will report results on Friday.

Inditex's sales between August and October rose 6 percent to 6.3 billion euros ($7.4 billion), in line with analysts' forecasts, against 10 percent growth in February-October. Third-quarter net profit rose 2.7 percent to 975 million euros.

"The top line is showing a big deceleration versus previous quarters," analysts from Kepler Cheuvreux wrote in a note.

They said most of the lower growth was already priced into the shares. Inditex shares have fallen about 5 percent so far this year, while H&M's have fallen almost 20 percent.

The arrival of chilly weather in November should boost Inditex's sales again, analysts said, and its shares opened up 4 percent.

Inditex said sales at its more than 7,500 stores and online increased 13 percent at constant exchange rates between Nov. 1 and Dec. 11, as shoppers snapped up items such as oversized sweaters and puffer parkas from new collections.

Analysts said the lower sales growth and a strong euro helped push Inditex's gross sales margin for the third quarter to 58.4 percent, down 33 basis points from the year before.

Inditex's profits are sensitive to fluctuations in the euro as it makes most of its clothes in the euro zone to respond quickly to fashion trends but generates more than half of its sales in countries outside the currency bloc

Inditex's business model has kept it consistently ahead of rivals such as H&M. By keeping its manufacturing bases close to its distribution center in the northern Spanish region of Galicia, it can shift new fashion trends from the catwalk to the shop window within weeks.

The Spanish retailer's other brands include teen label Bershka and underwear chain Oysho.

($1 = 0.8506 euros) (Reporting by Robert Hetz and Paul Day; Writing by Angus Berwick; Editing by Mark Potter)