The annual list ranks United above Real Madrid with Arsenal leapfrogging AC Milan into third spot and Chelsea in eighth position.
Meanwhile, David Beckham has lost top spot to Ronaldinho as the world’s highest-earning footballer.
Ten Premiership sides appear on Forbes’ list of the world’s 25 most valuable football teams followed by clubs from Italy (four), Germany (four), Spain (two), France (two), Scotland (two) and Holland (one).
The Forbes list however says United no longer command the largest yearly revenues as Real Madrid, Barcelona and Juventus – who all have own individual TV deals – surpassed their figure of £158m (€232m).
Salvatore Galatioto, president of the sports banking firm Galatioto Sports Partners, said China remains the key area for future growth.
He said: “A big reason why these teams are attracting suitors is their growth potential in all of Asia, but China is the key.
“You have great brands with these soccer teams that have not been fully exploited.”
Forbes say Beckham’s lucrative move to Los Angeles Galaxy at the end of the season could see the former England captain recapture his position as football’s highest earner.
Team valuations in pounds sterling according to Forbes:
1 Man Utd £740m
2 Real Madrid £528m
3 Arsenal £466m
4 Bayern Munich £427m
5 AC Milan £420m
6 Juventus £289m
7 Inter Milan £282m
8 Chelsea £274m
9 Barcelona £273m
10 Schalke 04 £240m
11 Liverpool £231m
12 Lyon £175m
13 Newcastle £132m
14 Tottenham £124m
15 Roma £114m
16 Hamburg £112m
17 Man City £106m
18 B Dortmund £101m
19 Ajax £100m
20 Celtic £94m
21 Everton £84m
22 Marseille £80m
23 West Ham £79m
24 Rangers £75m
25 Aston Villa £71m
Highest-earning players, according to Forbes:
1 Ronaldinho (Barcelona) £15.2m
2 David Beckham (Real Madrid) £14.8m
3 Ronaldo (AC Milan) £11.7m
4 Wayne Rooney (Man Utd) £8.7m
5 Michael Ballack (Chelsea) £8.7m
6 Thierry Henry (Arsenal) £8.2m
7 Zinedine Zidane (ex-Real Madrid) £8.2m
8 Fabio Cannavaro (Real Madrid) £7.6m
9 John Terry (Chelsea) £7.1m
10 Steven Gerrard (Liverpool) £7.1m