The two clubs share the same ownership group. The move reunites Fredricson with INEOS, who control both United and Lausanne-Sport, a link that Manchester United are understood to have built high-percentage sell-on and buyback clauses around, giving them the option to bring the 21-year-old back if he progresses well in Switzerland.
Fredricson had been close to joining Celtic in January but the move collapsed after an ill-timed injury; he returned to first-team training at Carrington earlier this month but sat out United's opening two pre-season matches while the Lausanne switch was finalised.
A boyhood United fan from south Manchester, Fredricson joined the club's academy in 2018 and signed his first professional contract in May 2022, the same year he played every round of United's FA Youth Cup-winning campaign, missing only the final itself. He went on to captain United's Under-21s regularly between 2022 and 2026.
His breakthrough senior appearances included two Premier League starts, but he did not feature after the club's shock EFL Cup second-round exit at League Two side Grimsby Town last season, with reports on his exact first-team tally varying between three and four appearances across competitions.
Lausanne-Sport, who finished ninth in the Swiss top flight last season under new head coach Luka Elsner, described Fredricson as arriving with "rare experience for a player of his age," while United thanked him for his efforts and wished him well for the next stage of his career.
The move continues a pattern of United moving on academy graduates who face limited first-team opportunities behind a squad of established internationals, with Fredricson joining a growing list of Carrington products to leave permanently in recent windows.
He follows Sekou Kone, another United academy product, who has already sealed a loan return to Lausanne-Sport this summer, underlining the pathway the Swiss club now offers for United's surplus young talent.