The 19-times English champions, who are preparing for a listing on the New York Stock Exchange, are valued at $2.23-billion, up from $1.86-billion last year and 19% above No2 Real Madrid ($1.88-billion).

All 32 National Football League franchises made the top 50 list, with the Dallas Cowboys, Washington Redskins, New England Patriots and Super Bowl champion New York Giants all securing spots in the top 10.

The only teams in the top 10 that do not play soccer or American football are Major League Baseball's New York Yankees, tied at third place with the Cowboys, and the Los Angeles Dodgers, who share the No6 spot with the Patriots.

The top 50 list includes seven soccer teams, with Arsenal falling three places to 10th overall and Barcelona rising 18 spots to eighth.

Ferrari is the top motor racing team, listed at No 15, whereas the New York Knicks - in 43rd place - are the only National Basketball Association franchise to make the list.

The Forbes top 10 teams are:

1. Manchester United - $2.23-billion

2. Real Madrid - $1.88-billion

3. New York Yankees - $1.85-billion

3. Dallas Cowboys - $1.85-billion

5. Washington Redskins - $1.56-billion

6. Los Angeles Dodgers - $1.40-billion

6. New England Patriots - $1.40-billion

8. Barcelona - $1.31-billion

9. New York Giants - $1.30-billion

10. Arsenal - $1.29-billion.