* Growth slows as Zalando did not expand into new markets
* Online fashion market to grow 14 pct this year - Mintel
BERLIN, Oct 23 (Reuters) - Europe's biggest online fashion retailer Zalando saw its growth rate slow in the second quarter due to the late arrival of the summer, with sales up 70 percent to 437 million euros ($602 million) compared to 74 percent in the first three months.
Berlin-based Zalando, which celebrated its fifth birthday last month with a fashion campaign fronted by Israeli supermodel Bar Rafaeli and which is now active in 14 markets, said sales for the first half rose 72 percent to 809 million euros.
"The summer season was not easy. Discounts were high as summer came late," Zalando managing director Rubin Ritter told Reuters. "As we have not expanded into new markets recently, the relative growth rate will naturally decrease."
Zalando has been extending its lead over British rival ASOS , doubling net sales to 1.2 billion euros last year although it made a loss before earnings and tax of around 80 million.
Online sales of clothes and shoes have exploded in recent years to become the most popular e-commerce category in most of Europe, with market research firm Mintel predicting the market will grow to about 38 billion euros in 2013 from 33.2 billion in 2012.