NEW YORK, Sept 13, 2023 (BSS/AFP) - German footwear brand Birkenstock on Tuesday filed for an initial public offering in the United States, planning to list its shares on the New York Stock Exchange.

The proposed terms of its share sale have not been revealed, but news reports previously said that the IPO could value the sandal maker at more than $8 billion.

An IPO marks a new milestone for the brand, after the Birkenstock family brought in its first external management team more than a decade ago.

The brand, founded in 1774 to make orthopedic shoes, received a Hollywood boost recently when actress Margot Robbie donned a pair of pink Birkenstocks in the lead role of the hit movie "Barbie."

By 1897, Konrad Birkenstock had made the first flexible sole fitting the contours of the feet, and the sandals made their way to the United States in the 1960s.

They were adopted by hippies who took to their no-frills comfort and also saw their utilitarian look as an anti-fashion badge of honor.

In 2021, private equity firm L Catterton and the family holding fund of French luxury brand magnate Bernard Arnault acquired a majority stake in Birkenstock, based in Linz am Rhein in western Germany.

Analysts estimated the price of the sale at around four billion euros ($4.4 billion).

The company has launched collaborations with brands such as Dior and Manolo Blahnik, and in the 2022 fiscal year saw revenues grow to some 1.2 billion euros, according to Tuesday's filing.

Two Birkenstock family members retain a minority stake.