Manchester United made close to £10m in sell-on clauses for Danny Drinkwater and Michael Keane in the summer.
The figure was revealed in the review of the club's quarterly accounts on Wednesday, which United made £17.3m from the sale of Adnan Januzaj and two sell-ons.
The £9.3m profit from those sell-ons derives from Chelsea's £35m purchase of Drinkwater from Leicester and Keane's £30m move from Burnley to Everton.
The remaining £8m transfer fee is from Januzaj's move to Real Sociedad.