ZURICH, Switzerland — Twenty-time Grand Slam tennis champion Roger Federer has bought a stake in Swiss running shoe manufacturer On, a move prompted by the end of his contract with Nike Inc. and as he plans for life after professional tennis, Swiss Sunday newspaper NZZ am Sonntag reported.

“I am excited to be able to work with a young Swiss company that’s on the up,” Federer was quoted as saying in extract of an interview to be published on Sunday. Without disclosing the actual size of his investment, Federer, 38, said he has put a substantial amount into the nine-year-old Zurich-based company.

“It’s a chunk of money big enough that I had to think about it carefully,” the newspaper cited him as saying. “I wanted to make a mark to show On how much I believe in the company and that I am planing for the long term with them.”

While Federer won’t take up a formal role at On, the company expects to release its first shoe that the star helped develop next year. On has 500 employees, 250 of which are based in Zurich. The company’s been profitable since 2014, the newspaper reported and, citing estimates, generates annual sales of as much as 200 million francs ($200 million).

Last year, Federer signed a contract with Fast Retailing Co. Ltd's Uniqlo brand that broadcaster ESPN reported to be worth $300 million over 10 years.

By Jan Dahinten ; editors: Alastair Reed, Sara Marley