FRANKFURT, Germany - Zalando, Europe's biggest online fashion retailer, priced its initial public offering on Wednesday in a range of 18.00 to 22.50 euros per share, which could value the company at up to 5.6 billion euros (4.4 billion pounds).

The Berlin-based company said it aimed to raise between 507 million euros and 633 million euros, including potential over-allotment shares.

The offering would represent about 11.3 percent of the company if all shares are placed and would be one of Germany's biggest technology stock flotations for years.

Zalando, which began in 2008 by selling shoes, has transformed itself into a general fashion retailer, shipping 1,500 brands to customers in 15 countries. It was inspired by the U.S. shoe and clothing retailer Zappos.com, which is now owned by Amazon.com.

The listing is part of a busy season for ecommerce IPOs, with Chinese giant Alibaba set to list as well as German venture-capital firm Rocket Internet, which helped launch Zalando and remains one of its major stakeholders.

Zalando said it already had cornerstone investments of about 127 million euros, including from Scottish Mortgage Investment Trust Plc.

The offer period is to start Thursday, with the first day of trading planned for Oct. 1 on the regulated market of the Frankfurt Stock Exchange, the company said. The listing will be co-managed by Morgan Stanley, Goldman Sachs and Credit Suisse.

The final price will be based on a book-building process for an offering that includes 24.48 million newly issued shares and 3.67 million additional shares available in the case of over-allotment.

All existing shareholders plan to remain fully invested, with the listing to be made up entirely of new, primary shares.

According to the company's prospectus, Swedish investment firm Kinnevik is Zalando's biggest shareholder and will have a post-IPO stake of around 31.6 percent, followed by a 14.8 percent stake held by the investment vehicle of Germany's Samwer brothers, who are the founders of Rocket Internet.

The figures assume full exercise of the over-allotment.

Zalando confirmed the first-half results it reported last month of sales rising by 29.5 percent to 1.047 billion euros, producing a small net profit, its first ever. In the prospectus it also reported first-half earnings before interest and taxes of 3.6 million euros, compared with a loss of 74.7 million euros in the first half of 2013.

Zalando said its current warehouse and fulfilment infrastructure is designed to handle about twice the level of sales generated in the 12 months ended in June. This will allow the company to maintain current investment levels while continuing to see revenue grow, it said.

"Going forward, we intend to focus on profitable growth. We aim to sustain growth at above-market rates", the company said.

It said it plans to achieve these goals by taking market share, increasing its active base of buyers and capturing a larger chunk of its customers' fashion spending. It cited as rivals Amazon.com, online fashion specialists ASOS, Boohoo and Yoox, and retail apparel chains such as H&M, Zara and Uniqlo.

At a news conference last month, a Zalando board member said the company could eventually expand to more markets in Eastern Europe from its core markets in Central and Western Europe.