(Reuters) - German online luxury retailer Mytheresa Group GmbH’s parent company said on Monday it had confidentially filed for an initial public offering in the United States. The move comes at a time when restrictions to stop the COVID-19 pandemic have led to a boom in ecommerce, with luxury online shopping thriving. The number of American depositary shares to be offered and the price range for Mytheresa’s proposed offering have not yet been determined, its parent company, MYT Netherlands Parent B.V, said in a statement. The firm, which sells clothes from 250 of the world"s biggest fashion brands including Prada, Gucci, Burberry and Dolce&Gabbana, may seek a valuation of $1 billion to $1.5 billion, according to a Bloomberg report here earlier this month, though the target could change based on the busy holiday season. Fashion retailers Susanne and Christoph Botschen in 1987 opened a store called Theresa in Munich, Germany, and they launched the online shop Mytheresa in 2006, with the business being purchased by luxury department store chain Neiman Marcus in 2014. Neiman Marcus, which filed for bankruptcy earlier this year, pressured by store closures and dwindling sales, handed over a part of Mytheresa to its creditors to exit Chapter 11. Earlier this month, Mytheresa’s rival Farfetch attracted more than $1 billion in investment from Alibaba and Swiss group Richemont.