United are expected to save within the region of £40m after allowing the Chilean to make his season-long loan spell at the Giuseppe Meazza permanent.
The Old Trafford club have made a ‘small’ pay-off to cover some of Sanchez’s basic salary, which stood in the region of £350,000-a-week before significant bonuses and image rights payments.
The Chile international's contract still had two years left to run, having joined from Arsenal in January 2018 in a swap deal which saw Henrikh Mkhitaryan move in the opposite direction.
Despite arriving as one of the Premier League’s most prolific attacking players, Sanchez scored just five goals in 45 appearances and struggled to establish himself under both Jose Mourinho and his successor Ole Gunnar Solskjaer.
Sanchez was allowed to spend the 2019-20 season on loan at Inter, where a run of three goals and seven assists post-lockdown has helped to convince the Serie A club to negotiate a permanent deal.
The 31-year-old has unsurprisingly taken a significant pay cut - believed to be approximately £120,000-a-week - to join up with Antonio Conte's side on a three-year contract.
Sanchez could now face his former employers in the Europa League final on 21 August, should both United and Inter progress through next week's eight-team mini-tournament in Cologne.
In a club statement, United said: “Everyone at Manchester United wishes Alexis Sanchez all the best in his future career as he joins Inter Milan on a permanent transfer.”
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