Manchester City's wealthy owner Sheikh Mansour bin Zayed Al Nahyan has toppled Roman Abramovich to head British football's rich list, according to FourFourTwo magazine.
David Beckham remains the richest player associated with British football with a personal fortune of £125m.
Professor Tom Cannon told FourFourTwo that this level of wealth in football cannot last in the current financial climate.
"Season-ticket numbers will probably be down by about 10 per cent but renewals will be down by at least 15 or 20 per cent. That's where the problems will be as you go down the divisions."
RICH LIST TOP TEN:
1 Sheikh Mansour bin Zayed Al Nahyan (Man City) £15bn
2 Lakshmi Mittal and family (QPR) £12.5bn
3 Roman Abramovich (Chelsea) £7bn
4 Joe Lewis (Tottenham) £2.5bn
5 Bernie and Slavica Ecclestone (QPR) £2.4bn
6 Stanley Kroenke (Arsenal) £2.24bn
7 Alisher Usmanov (Arsenal) £1.5bn
8 Lord Grantchester/the Moores Family (Everton) £1.2bn
8 Dermot Desmond (Celtic) £1.2bn
10 Lord Ashcroft (Watford) £1.1bn
10 Malcolm Glazer and family (Man Utd) £1.1bn
TOP TEN PLAYERS
1 David Beckham £125m
2 Michael Owen £40m
3 Wayne Rooney £35m
4 Rio Ferdinand £28m
4 Robbie Fowler £28m
4 Sol Campbell £28m
7 Ryan Giggs £23m
8 Michael Ballack £20m
8 Frank Lampard £20m
10 Steven Gerrard £19m