BERLIN, March 16 (Reuters) - Qatar's sovereign wealth fund has taken a stake in Rocket Internet's RKET.DE recipe and ingredients business HelloFresh as part of a previously announced fundraising, the German company said on Thursday.

Founded in Berlin in 2007, Rocket has built up dozens of businesses from fashion e-commerce to food delivery, but many investors have become concerned about heavy losses and falling valuations for its key start-ups.

Rocket Internet said in December that HelloFresh had raised 85 million euros ($91.16 million) from an unnamed leading global investor and existing shareholder Baillie Gifford, at a 2 billion euro valuation, down from a previous 2.6 billion euros.

On Thursday German magazine WirtschaftsWoche cited HelloFresh Chief Executive Dominik Richter as saying that Qatar had been part of the fundraising.

A spokeswoman for HelloFresh confirmed the report, saying it was very happy to welcome Qatar as a long-term investor, noting that the fund usually only invests in big corporations and listed companies.

Shares in Rocket Internet dropped last month after major investor Kinnevik KINVb.ST sold half its stake in the German e-commerce company as the two increasingly become competitors.

Rocket Internet's stake in HelloFresh now stands at 53 percent. HelloFresh is one of its biggest holdings and is viewed as a potential candidate for an initial public offering, though a previous attempt to list the business stalled in 2015. ($1 = 0.9324 euros)

(Reporting by Emma Thomasson; Editing by Christoph Steitz and David Goodman) ((+49 30 2888 5081; Reuters Messaging: emma.thomasson.thomsonreuters.com@reuters.net))