The company said in a statement on Friday that L Catterton affiliates including Arnault’s family investment company, Financière Agache, will also invest in the maker of the iconic flat sandals. Arnault is Europe’s richest person, with an estimated net worth of $117 billion, according to the Bloomberg Billionaires Index.”In L Catterton and Financière Agache we have found not just shareholders, but also partners for achieving our global growth ambitions,” said CEO Oliver Reichert, who is one of the company’s first leaders to come from outside the Birkenstock family.The secret of Birkenstock's enduring successBrothers Christian and Alex Birkenstock will keep a minority stake, according to the Financial Times, which reported that the deal valued the company at €4 billion ($4.8 billion). Birkenstock declined to comment on the financial details of the transaction.The company traces its roots to 1774 and is the largest employer in the German shoe industry, according to its website. Its sandals have long been a staple of celebrities and fashion icons, such as Heidi Klum, Kendall Jenner and Alexa Chung. Read MoreLast July, British Vogue declared Birkenstock the official sandals of 2020 and they were one of the most sought after items of clothing during the pandemic, according to online fashion retailer Lyst.In the statement on Friday, Birkenstock said it is “performing better than ever before.” Under its new owners, it plans to grow in markets such as China and India and expand production in Germany. It will also invest in e-commerce platforms and its direct-to-consumer business.L Catterton was formed in 2016 when LVMH and Groupe Arnault joined forces with US private equity firm Catterton.”Birkenstock was founded nearly 250 years ago and has grown to become one the few iconic brands in the footwear industry. We truly appreciate brands with this long heritage,” Arnault said in a statement.Birkenstock has 4,300 employees worldwide.