Nike will end its longtime deal to supply kits for Manchester United with the club expected to sign with Adidas.
The current agreement expires next year.
"Clearly Nike's football business is booming and they could easily afford to do this (deal). They had the right to match any other offer but looking at the deal on the table, they will walk away as it doesn't make commercial sense," the source said.
United got around 38 million pounds ($64.7 million) from the Nike deal in 2012-13, including its share of profit from the sale of merchandise around the world.
Media reports had suggested the club was looking for a new deal worth around 60 million pounds per season.