The Red Devils are the most successful team in Premier League history, winning 13 league titles under Sir Alex Ferguson.
However, Bayern have won the Bundesliga title for the last four seasons and are on course for a fifth this campaign, as they sit 13 points ahead of second spot.
“I have come to a club that has a great and prestigious history, but no club in England, whether it's Manchester United, Liverpool or Manchester City can be dominant permanently. Power has divided,” Mourinho told France Football.
“In England, clubs are so economically powerful that the transfer market is open to everyone.
“Take the example of Bayern in Germany.
“You know when they begin to win the title every year? When, the summer before, they buy the best players of Borussia Dortmund! Mario Gotze, then Robert Lewandowski the following year, then Mats Hummels last year.”