The cost of signing Harry Maguire, Aaron Wan-Bissaka and Daniel James ahead of the new season in the first quarter of the financial year was around 140 million pounds.
Although United reported record revenue last season of 627.1 million pounds, the New York Stock Exchange listed business is now expecting the 2019-20 figure to drop to between 560 million and 580 million pounds.
That is due to United missing out on Champions League television and prize money after finishing sixth last season. United could miss out again with the side in seventh place, nine points behind fourth-placed Manchester City after 12 of the 38 games.
"Our ultimate aim is to win trophies, play fast, fluid, attacking football, with a team that uses graduates from our academy along with world-class acquisitions,” United executive vice chairman Ed Woodward said. “We know this will not be achieved overnight, however we have made investments across the club that we believe will set us on the right path.
"We know our academy is a strong competitive advantage and an area we will continue to invest in as it is at the heart of the club."